Compound, material for organic electroluminescent element, organic electroluminescent element, and electronic device

ABSTRACT

An organic EL device capable of driving at low voltage and having high emission efficiency and long lifetime and a material for organic EL devices which realize such an organic EL device are provided. The material for organic EL devices is a compound represented by formula (A1) or (B1): 
     
       
         
         
             
             
         
       
     
     wherein R 1  to R 8 , n1, m2, k3, k4, n5, m6, L 0  to L 2 , and Ar are as defined in the description.

TECHNICAL FIELD

The present invention relates to compounds, materials for organicelectroluminescence devices comprising the compounds, organicelectroluminescence devices comprising the compounds, and electronicequipment comprising the organic electroluminescence devices.

BACKGROUND ART

An organic electroluminescence device (also referred to as “organic ELdevice”) is generally composed of an anode, a cathode, and one or moreorganic thin film layers which comprise a light emitting layer and aresandwiched between the anode and the cathode. When a voltage is appliedbetween the electrodes, electrons are injected from the cathode andholes are injected from the anode into a light emitting region. Theinjected electrons recombine with the injected holes in the lightemitting region to form excited states. When the excited states returnto the ground state, the energy is released as light. Therefore, it isimportant for increasing the efficiency of an organic EL device todevelop a compound which transports electrons or holes into the lightemitting region efficiently and facilitates the recombination ofelectrons and holes.

The drive of an organic EL device at lower voltage is effective forreducing the power consumption and also effective for improving theemission efficiency and the device lifetime. To reduce the drivingvoltage, a charge transporting material having a high electron mobilityand/or a high hole mobility is required, and many proposals have beenmade on such a charge transporting material.

CITATION LIST Patent Literature

-   Patent Literature 1: WO 2014/015935-   Patent Literature 2: WO 2014/015937-   Patent Literature 3: WO 2011/021520

SUMMARY OF INVENTION Technical Problem

An object of the present invention is to provide an organic EL devicewhich is capable of driving at a lower voltage and has high emissionefficiency and long lifetime and also provide a material for organic ELdevices which realizes such an organic EL device.

Solution to Problem

As a result of extensive research in view of achieving the above object,the inventors have found that a compound represented by formula (A1) or(B1) has a large energy gap and a high hole mobility, and further foundthat an organic EL device which is capable of driving at a lower voltageand has high emission efficiency and long lifetime is obtained by usingthe compound.

In an aspect of the invention, the following (1) to (4) are provided:

-   (1) a compound represented by formula (A1) or (B1):

wherein R¹ to R⁶ each independently represent a substituted orunsubstituted alkyl group having 1 to 20 carbon atoms, a substituted orunsubstituted aryl group having 6 to 50 ring carbon atoms, a substitutedor unsubstituted heteroaryl group having 5 to 50 ring atoms, a halogenatom, a substituted or unsubstituted fluoroalkyl group having 1 to 20carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20carbon atoms, a substituted or unsubstituted fluoroalkoxy group having 1to 20 carbon atoms, a substituted or unsubstituted aryloxy group having6 to 50 ring carbon atoms, or a cyano group;

when R¹ to R⁶ are each plurality in number, groups R¹ to groups R⁶ maybe the same or different; R⁵ and R⁶ may be bonded to each other to forma ring structure;

R⁷ and R⁸ each independently represent a hydrogen atom, a substituted orunsubstituted alkyl group having 1 to 20 carbon atoms, a substituted orunsubstituted fluoroalkyl group having 1 to 20 carbon atoms, or a cyanogroup, and R⁷ and R⁸ may be bonded to each other to form a saturatedaliphatic ring;

k3 and k4 each independently represent an integer of 0 to 5, m2 and m6each independently represent an integer of 0 to 4, and n1 and n5 eachindependently represent an integer of 0 to 3;

L⁰ to L² each independently represent a single bond, a substituted orunsubstituted arylene group having 6 to 50 ring carbon atoms, or asubstituted or unsubstituted heteroarylene group having 5 to 50 ringatoms;

Ar represents a substituted or unsubstituted aryl group having 6 to 50ring carbon atoms or a substituted or unsubstituted heteroaryl grouphaving 5 to 40 ring atoms;

-   (2) a material for organic electroluminescence devices comprising    the compound according to (1);-   (3) an organic electroluminescence device which comprises a cathode,    an anode, and at least one organic thin film layer disposed between    the cathode and the anode, wherein the at least one organic thin    film layer comprises a light emitting layer and at least one layer    of the at least one organic thin film layer comprises the compound    according to (1); and-   (4) an electronic equipment comprising the organic    electroluminescence device according to (3).

Advantageous Effects of Invention

An organic EL device which is capable of driving at a lower voltage andhas high emission efficiency and long lifetime is obtained by using thecompound represented by formula (1) as the material for organic ELdevices. Particularly, the effect of improving the lifetime is large.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic illustration of the structure of an organic ELdevice in an aspect of the present invention.

DESCRIPTION OF EMBODIMENTS

The term of “XX to YY carbon atoms” referred to by “a substituted orunsubstituted group ZZ having XX to YY carbon atoms” used herein is thenumber of carbon atoms of the unsubstituted group ZZ and does notinclude any carbon atom in the substituent of the substituted group ZZ.

The term of “XX to YY atoms” referred to by “a substituted orunsubstituted group ZZ having XX to YY atoms” used herein is the numberof atoms of the unsubstituted group ZZ and does not include any atom inthe substituent of the substituted group ZZ.

The number of “ring carbon atoms” referred to herein means the number ofthe carbon atoms included in the atoms which are members forming thering itself of a compound in which a series of atoms is bonded to form aring (for example, a monocyclic compound, a fused ring compound, across-linked compound, a carbocyclic compound, and a heterocycliccompound). If the ring has a substituent, the carbon atom in thesubstituent is not included in the ring carbon atom. The same applies tothe number of “ring carbon atom” described below, unless otherwisenoted. For example, a benzene ring has 6 ring carbon atoms, anaphthalene ring has 10 ring carbon atoms, a pyridinyl group has 5 ringcarbon atoms, and a furanyl group has 4 ring carbon atoms. If a benzenering or a naphthalene ring has, for example, an alkyl substituent, thecarbon atom in the alkyl substituent is not counted as the ring carbonatom of the benzene or naphthalene ring. In case of a fluorene ring towhich a fluorene substituent is bonded (inclusive of a spirofluorenering), the carbon atom in the fluorene substituent is not counted as thering carbon atom of the fluorene ring.

The number of “ring atom” referred to herein means the number of theatoms which are members forming the ring itself (for example, amonocyclic ring, a fused ring, and a ring assembly) of a compound inwhich a series of atoms is bonded to form the ring (for example, amonocyclic compound, a fused ring compound, a cross-linked compound, acarbocyclic compound, and a heterocyclic compound). The atom not formingthe ring (for example, hydrogen atom(s) for saturating the valence ofthe atom which forms the ring) and the atom in a substituent, if thering is substituted, are not counted as the ring atom. The same appliesto the number of “ring atoms” described below, unless otherwise noted.For example, a pyridine ring has 6 ring atoms, a quinazoline ring has 10ring atoms, and a furan ring has 5 ring atoms. The hydrogen atom on thering carbon atom of a pyridine ring or a quinazoline ring and the atomin a substituent are not counted as the ring atom. In case of a fluorenering to which a fluorene substituent is bonded (inclusive of aspirofluorene ring), the atom in the fluorene substituent is not countedas the ring atom of the fluorene ring.

The definition of “hydrogen atom” used herein includes isotopesdifferent in the neutron numbers, i.e., light hydrogen (protium), heavyhydrogen (deuterium), and tritium.

The terms of “heteroaryl group” and “heteroarylene group” used hereinmeans a group having at least one hetero atom as a ring atom. The heteroatom is preferably at least one selected from a nitrogen atom, an oxygenatom, a sulfur atom, a silicon atom, and a selenium atom.

The optimal substituent referred to by “substituted or unsubstituted”used herein is preferably selected from the group consisting of an alkylgroup having 1 to 50, preferably 1 to 18, more preferably 1 to 8 carbonatoms; a cycloalkyl group having 3 to 50, preferably 3 to 10, morepreferably 3 to 8, still more preferably 5 or 6 ring carbon atoms; anaryl group having 6 to 50, preferably 6 to 25, more preferably 6 to 18ring carbon atoms; an aralkyl group having 7 to 51, preferably 7 to 30,more preferably 7 to 20 carbon atoms which includes an aryl group having6 to 50, preferably 6 to 25, more preferably 6 to 18 ring carbon atoms;an amino group; an alkoxy group having an alkyl group having 1 to 50,preferably 1 to 18, more preferably 1 to 8 carbon atoms; an aryloxygroup having an aryl group having 6 to 50, preferably 6 to 25, morepreferably 6 to 18 ring carbon atoms; a mono-, di- or tri-substitutedsilyl group, wherein the substituent is selected from an alkyl grouphaving 1 to 50, preferably 1 to 18, more preferably 1 to 8 carbon atomsand an aryl group having 6 to 50, preferably 6 to 25, more preferably 6to 18 ring carbon atoms; a heteroaryl group having 5 to 50, preferably 5to 24, more preferably 5 to 13 ring atoms; a haloalkyl group having 1 to50, preferably 1 to 18, more preferably 1 to 8 carbon atoms; a halogenatom selected from a fluorine atom, a chlorine atom, a bromine atom andan iodine atom; a cyano group; a nitro group; a substituted sulfonylgroup, wherein the substituent is selected from an alkyl group having 1to 50, preferably 1 to 18, more preferably 1 to 8 carbon atoms and anaryl group having 6 to 50, preferably 6 to 25, more preferably 6 to 18ring carbon atoms; a di-substituted phosphoryl group, wherein thesubstituent is selected from an alkyl group having 1 to 50, preferably 1to 18, more preferably 1 to 8 carbon atoms and an aryl group having 6 to50, preferably 6 to 25, more preferably 6 to 18 ring carbon atoms; analkylsulfonyloxy group; an arylsulfonyloxy group; an alkylcarbonyloxygroup; an arylcarbonyloxy group; a boron-containing group; azinc-containing group; a tin-containing group; a silicon-containinggroup; a magnesium-containing group; a lithium-containing group; ahydroxyl group; an alkyl-substituted or aryl-substituted carbonyl group;a carboxyl group; a vinyl group; a (meth)acryloyl group; an epoxy group;and an oxetanyl group.

The optional substituent may further has the substituent mentionedabove. The optional substituents may be bonded to each other to form aring.

The term of “unsubstituted” referred to by “substituted orunsubstituted” used herein means that no hydrogen atom in a group issubstituted by a substituent.

Of the above substituents, more preferred are an alkyl group having 1 to50, preferably 1 to 18, more preferably 1 to 8 carbon atoms; acycloalkyl group having 3 to 50, preferably 3 to 10, more preferably 3to 8, still more preferably 5 or 6 ring carbon atoms; an aryl grouphaving 6 to 50, preferably 6 to 25, more preferably 6 to 18 ring carbonatoms; a heteroaryl group having 5 to 50, preferably 5 to 24, morepreferably 5 to 13 ring atoms; a halogen atom; and a cyano group.

In the present invention, those which are defined as being preferred canbe selected arbitrarily.

Compound

In an aspect of the invention, a compound represented by formula (A1)(also referred to as “compound (A1)”) and a compound represented byformula (B1) (also referred to as “compound (B1)”) are provided. Thecompound (A1) and the compound (B1) may be collectively referred as“compound (1).” The compound (1) is useful as a material for organicelectroluminescence devices.

R¹ to R⁸ in Formulae (A1) and (B1)

R¹ to R⁶ in formula (A1) or (B1) each represent a substituent which isbonded to a carbon atom of each benzene ring in each formula.

R¹ to R⁶ each independently represent a substituted or unsubstitutedalkyl group having 1 to 20, preferably 1 to 8, and more preferably 1 to3 carbon atoms; a substituted or unsubstituted aryl group having 6 to50, preferably 6 to 25, more preferably 6 to 18, and still morepreferably 6 to 12 ring carbon atoms; a substituted or unsubstitutedheteroaryl group having 5 to 50, preferably 5 to 10, more preferably 5to 8, and still more preferably 5 or 6 ring atoms; a halogen atom, asubstituted or unsubstituted fluoroalkyl group having 1 to 20,preferably 1 to 5, and more preferably 1 to 4 carbon atoms; asubstituted or unsubstituted alkoxy group having 1 to 20, preferably 1to 5, and more preferably 1 to 4 carbon atoms; a substituted orunsubstituted fluoroalkoxy group having 1 to 20, preferably 1 to 5, andmore preferably 1 to 4 carbon atoms; a substituted or unsubstitutedaryloxy group having 6 to 50, preferably 6 to 25, more preferably 6 to18, and still more preferably 6 to 12 ring carbon atoms; or a cyanogroup.

Of the above, R¹ to R⁶ each independently and preferably represent agroup selected from the group consisting of a substituted orunsubstituted alkyl group having 1 to 20 carbon atoms, a substituted orunsubstituted heteroaryl group having 5 to 50 ring atoms, and a halogenatom, with a substituted or unsubstituted alkyl group having 1 to 20carbon atoms being more preferred.

The subscripts k3 and k4 each independently represent an integer of 0 to5, preferably an integer of 0 to 2, more preferably 0 or 1, and stillmore preferably 0;

m2 and m6 each independently represent an integer of 0 to 4, preferablyan integer of 0 to 2, more preferably 0 or 1, and still more preferably0; and

n1 and n5 each independently represent an integer of 0 to 3, preferablyan integer of 0 to 2, more preferably 0 or 1, and still more preferably0.

When k3, k4, m2, m6, n1, and n5 are each 0, each benzene ring has nosubstituent.

When R¹ to R⁶ are each plurality in number, groups R¹ to groups R⁶ maybe the same or different.

In an embodiment of the invention, two selected from R¹ to R⁴ are notbonded to each other, thereby failing to form a ring structure.

In another embodiment of the invention, R⁵ and R⁶ may be bonded to eachother to form a ring structure. In a preferred embodiment, R⁵ and R⁶ arenot bonded to each other to fail to form a ring structure.

R⁷ and R⁸ each independently represent a hydrogen atom, a substituted orunsubstituted alkyl group having 1 to 20 carbon atoms, a substituted orunsubstituted fluoroalkyl group having 1 to 20 carbon atoms, or a cyanogroup. R⁷ and R⁸ may be bonded to each other to form a saturatedaliphatic ring. In a preferred embodiment, R⁷ and R⁸ are not bonded toeach other, thereby failing to form a saturated aliphatic ring.

Of the above, preferably R⁷ and R⁸ each independently represent asubstituted or unsubstituted alkyl group having 1 to 20 carbon atoms. R⁷and R⁸ may be different, preferably the same, and more preferably eachrepresent a substituted or unsubstituted alkyl group having 1 to 20carbon atoms.

The structure wherein R⁷ and R⁸ are bonded to each other to form asaturated aliphatic ring includes, for example, the following structure:

wherein R⁵, R⁶, n5, and m6 are as defined in formula (A1).

Examples of the alkyl group having 1 to 20 carbon atoms include a methylgroup, an ethyl group, a n-propyl group, an isopropyl group, a n-butylgroup, an isobutyl group, a s-butyl group, a t-butyl group, a pentylgroup (inclusive of isomeric groups), a hexyl group (inclusive ofisomeric groups), a heptyl group (inclusive of isomeric groups), anoctyl group (inclusive of isomeric groups), a nonyl group (inclusive ofisomeric groups), a decyl group (inclusive of isomeric groups), anundecyl group (inclusive of isomeric groups), and a dodecyl group(inclusive of isomeric groups).

Of the above, preferred are a methyl group, an ethyl group, a n-propylgroup, an isopropyl group, a n-butyl group, an isobutyl group, a s-butylgroup, a t-butyl group, and a pentyl group (inclusive of isomericgroups), with a methyl group, an ethyl group, a n-propyl group, anisopropyl group, a n-butyl group, an isobutyl group, a s-butyl group,and a t-butyl group being more preferred, and a methyl group and at-butyl group being still more preferred.

Examples of the aryl group having 6 to 50 ring carbon atoms include aphenyl group, a naphthylphenyl group, a biphenylyl group, a terphenylylgroup, a biphenylenyl group, a naphthyl group, a phenylnaphthyl group,an acenaphthylenyl, an anthryl group, a benzanthryl group, an aceanthrylgroup, a phenanthryl group, a benzophenanthryl group, a phenalenylgroup, a fluorenyl group, a 9,9-dimethylfluorenyl group, a7-phenyl-9,9-dimethylfluorenyl group, a pentacenyl group, a picenylgroup, a pentaphenyl group, a pyrenyl group, a chrysenyl group, abenzochrysenyl group, a s-indacenyl group, an as-indacenyl group, afluoranthenyl group, and a perylenyl group.

Of the above, preferred are a phenyl group, a naphthylphenyl group, abiphenylyl group, a terphenylyl group, a naphthyl group, and a9,9-dimethylfluorenyl group, with a phenyl group, a biphenylyl group, anaphthyl group, and a 9,9-dimethylfluorenyl group being more preferred,and a phenyl group being still more preferred.

The heterocyclic group having 5 to 50 ring atoms comprises at least one,preferably 1 to 3 hetero atoms which may be the same or different, suchas a nitrogen atom, a sulfur atom and an oxygen atom.

Examples of the heterocyclic group include a pyrrolyl group, a furylgroup, a thienyl group, a pyridyl group, a pyridazinyl group, apyrimidinyl group, a pyrazinyl group, a triazinyl group, an imidazolylgroup, an oxazolyl group, a thiazolyl group, a pyrazolyl group, anisoxazolyl group, an isothiazolyl group, an oxadiazolyl group, athiadiazolyl group, a triazolyl group, an indolyl group, an isoindolylgroup, a benzofuranyl group, an isobenzofuranyl group, a benzothiophenylgroup, an indolizinyl group, a quinolizinyl group, a quinolyl group, anisoquinolyl group, a cinnolyl group, a phthalazinyl group, aquinazolinyl group, a quinoxalinyl group, a benzimidazolyl group, abenzoxazolyl group, a benzothiazolyl group, an indazolyl group, abenzisoxazolyl group, a benzisothiazolyl group, a dibenzofuranyl group,a dibenzothiophenyl group, a phenanthridinyl group, an acridinyl group,a phenanthrolinyl group, a phenazinyl group, a phenothiazinyl group, aphenoxazinyl group, and a xanthenyl group.

Of the above, preferred are a furyl group, a thienyl group, a pyridylgroup, a pyridazinyl group, a pyrimidinyl group, a pyrazinyl group, atriazinyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, and a dibenzothiophenyl group, with a benzofuranylgroup, a benzothiophenyl group, a dibenzofuranyl group, and adibenzothiophenyl group being more preferred.

Examples of the halogen atom include a fluorine atom, a chlorine atom, abromine atom, and an iodine atom, with a fluorine atom being preferred.

Examples of the fluoroalkyl group having 1 to 20 carbon atoms include,for example, those derived from the above alkyl group having 1 to 20carbon atoms by replacing at least one hydrogen atom, preferably 1 to 7hydrogen atoms or all hydrogen atoms with a fluorine atom or fluorineatoms.

Preferred examples thereof are a heptafluoropropyl group, apentafluoroethyl group, a 2,2,2-trifluoroethyl group, and atrifluoromethyl group, with a pentafluoroethyl group, a2,2,2-trifluoroethyl group, and a trifluoromethyl group being morepreferred, and a trifluoromethyl group being still more preferred.

The alkoxy group having 1 to 20 carbon atoms is represented by —OR^(X),wherein R^(X) is the above alkyl group having 1 to 20 carbon atoms.

Preferred examples thereof include a t-butoxy group, a propoxy group, anethoxy group, and a methoxy group, with an ethoxy group and a methoxygroup being more preferred, and a methoxy group being still morepreferred.

The fluoroalkoxy group having 1 to 20 carbon atoms is represented by—OR^(Y), wherein R^(Y) is the above fluoroalkyl group having 1 to 20carbon atoms.

Preferred examples thereof include a heptafluoropropoxy group, apentafluoroethoxy group, a 2,2,2-trifluoroethoxy group, and atrifluoromethoxy group, with a pentafluoroethoxy group, a2,2,2-trifluoroethoxy group, and a trifluoromethoxy group being morepreferred, and a trifluoromethoxy group being still more preferred.

The aryloxy group having 6 to 50 ring carbon atoms is represented by—OR^(Z), wherein R^(Z) is the above aryl group having 6 to 50 ringcarbon atoms.

Preferred examples thereof include a phenyloxy group, 1-naphthyloxygroup, 2-naphthyloxy group, a 4-biphenylyloxy group, ap-terphenyl-4-yloxy group, and a p-tolyloxy group, with a phenyloxygroup and a 2-naphthyloxy group being more preferred and a phenyloxygroup being still more preferred.

L⁰ to L² in formulae (A1) and (B1)

In formulae (A1) and (B1), L⁰ to L² each independently represent asingle bond, a substituted or unsubstituted arylene group having 6 to50, preferably 6 to 24, and more preferably 6 to 12 ring carbon atoms,or a substituted or unsubstituted heteroarylene group having 5 to 50,preferably 5 to 10, more preferably 5 to 8, and still more preferably 5or 6 ring atoms.

Examples of the arylene group having 6 to 50 ring carbon atoms includedivalent groups obtained by removing one hydrogen atom from the arylgroup having 6 to 50 ring carbon atoms mentioned above with respect toR¹ to R⁸.

Preferred examples thereof include a terphenyldiyl group (inclusive ofisomeric groups), a biphenyldiyl group (inclusive of isomeric groups),and a phenylene group (inclusive of isomeric groups), with abiphenyldiyl group (inclusive of isomeric groups) and a phenylene group(inclusive of isomeric groups) being more preferred, a4,4′-biphenyldiyl, an o-phenylene group, a m-phenylene group, and ap-phenylene group being still more preferred, and a p-phenylene groupbeing further preferred.

The substituted or unsubstituted heteroarylene group having 5 to 50 ringatoms comprises at least one, preferably 1 to 3 hetero atoms which maybe the same or different, such as a nitrogen atom, a sulfur atom and anoxygen atom.

Examples thereof include divalent groups obtained by removing onehydrogen atom from the heteroaryl group having 5 to 50 ring atomsmentioned above with respect to R¹ to R⁸.

Preferred examples thereof include a furylene group, a thienylene group,a pyridylene group, a pyridazinylene group, a pyrimidinylene group, apyrazinylene group, a triazinylene group, a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, and adibenzothiophenylene group, with a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, and adibenzothiophenylene group being more preferred.

L¹ is bonded to one of the carbon atoms at 1-, 2-, 3- and 4-positions(carbon atoms *1, *2, *3, and *4) of the following fluorene skeletonhaving R⁷ and R⁸ at its 9-position which is shown in formula (A1) andpreferably bonded to carbon atom at 2-position (carbon atom *2).

L⁰ to L² each preferably represent a single bond or a substituted orunsubstituted arylene group having 6 to 50 ring carbon atoms, morepreferably a single bond or a group represented by any of formulae (i)and (ii), still more preferably a single bond or a group represented byformula (i), and further preferably a single bond.

Particularly, L⁰ is preferably a single bond or a substituted orunsubstituted arylene group having 6 to 50 ring carbon atoms.

In formulae (i) and (ii), * and ** each represent a bonding site,wherein one of * and ** is the bonding site to the nitrogen atom informula (A1) or (B1) and the other is the bonding site to Ar in formula(A1) or (B1) or the benzene ring in the fluorene skeleton in formula(A1) or (B1).

Each R and preferred examples thereof are independently the same asthose described with respect to R¹ in formulae (A1). Each R is asubstituent which is bonded to the carbon atom of each benzene ring informulae (i) and (ii).

In an embodiment of the invention, when more than one R occurs, groups Rmay be the same or different. In another embodiment of the invention,two selected from groups R may be bonded to each other to form a ringstructure. Examples of the ring structure include an aromatic ring and apartially saturated hydrocarbon ring. The number of ring carbon atom ofthe aromatic ring is, but not particularly limited to, preferably 6 to14, more preferably 6 to 10, and still more preferably 6. The number ofring carbon atom of the partially saturated hydrocarbon ring is, but notparticularly limited to, preferably 5 to 10, more preferably 5 to 8, andstill more preferably 5 or 6.

Examples of formula (i) wherein a ring structure is formed are shownbelow:

wherein * and ** are as defined in formula (i).

Examples of formula (ii) wherein a ring structure is formed are shownbelow:

wherein * and ** are as defined in formula (ii).

In formulae (i) and (ii), each m independently represents an integer of0 to 4, preferably an integer of 0 to 2, more preferably 0 or 1, andstill more preferably 0.

When m is 0, each benzene ring has no substituent.

The group represented by formula (i) is preferably represented byformula (i-a), and the group represented by formula (ii) is preferablyrepresented by formula (ii-a). Particularly, L⁰ to L² in formulae (A1)and (B1) are each preferably represent a single bond or a grouprepresented by any of formulae (i-a) and (ii-a):

wherein R, m, *, and ** are as defined in formulae (i) and (ii).

In view of low voltage drive, emission efficiency and lifetime, L¹ informula (B1) is more preferably a substituted or unsubstituted arylenegroup having 6 to 50, preferably 6 to 24, and more preferably 6 to 12ring carbon atoms or a substituted or unsubstituted heteroarylene grouphaving 5 to 50, preferably 5 to 10, more preferably 5 to 8, and stillmore preferably 5 or 6 ring atoms.

In view of low voltage drive, emission efficiency and lifetime, L² informula (B1) is more preferably a substituted or unsubstituted arylenegroup having 6 to 50, preferably 6 to 24, and more preferably 6 to 12ring carbon atoms or a substituted or unsubstituted heteroarylene grouphaving 5 to 50, preferably 5 to 10, more preferably 5 to 8, and stillmore preferably 5 or 6 ring atoms.

Further, in a still more preferred formula (B1), L⁰ is a single bond andL¹ is a substituted or unsubstituted arylene group having 6 to 50,preferably 6 to 24, and more preferably 6 to 12 ring carbon atoms or asubstituted or unsubstituted heteroarylene group having 5 to 50,preferably 5 to 10, more preferably 5 to 8, and still more preferably 5or 6 ring atoms. Namely, in formula (B1-1) to be described below, L¹ ispreferably a substituted or unsubstituted arylene group having 6 to 50,preferably 6 to 24, and more preferably 6 to 12 ring carbon atoms or asubstituted or unsubstituted heteroarylene group having 5 to 50,preferably 5 to 10, more preferably 5 to 8, and still more preferably 5or 6 ring atoms.

In particular, in formula (B1), preferably none of a naphthalene ringand a phenanthrene ring is directly bonded to the nitrogen atom (N)shown in formula (B1), and more preferably none of a naphthalene ring, aphenanthrene, a dibenzofuran ring, and a dibenzothiophene ring isdirectly bonded to the nitrogen atom (N) shown in formula (B1). This isequally applied to formula (A1), i.e., preferably none of a naphthalenering and a phenanthrene is directly bonded to the nitrogen atom (N)shown in formula (A1) and more preferably none of a naphthalene ring, aphenanthrene, a dibenzofuran ring, and a dibenzothiophene ring isdirectly bonded to the nitrogen atom (N) shown in formula (A1).

Ar in Formula (A1)

In formula (A1), Ar represents s substituted or unsubstituted aryl grouphaving 6 to 50, preferably 6 to 25, more preferably 6 to 18, and stillmore preferably 6 to 12 ring carbon atoms or a substituted orunsubstituted heteroaryl group having 5 to 50, preferably 5 to 10, morepreferably 5 to 8, and still more preferably 5 or 6 ring atoms.

Examples of the aryl group having 6 to 50 ring carbon atoms and theheteroaryl group having 5 to 50 ring atoms are the same as thosedescribed above with respect to R¹ to R⁸.

When the compound of the invention is used as a material for a secondhole transporting layer of an organic EL device which comprises atwo-layered hole transporting layer having a first hole transportinglayer (anode side) and a second hole transporting layer (light emittinglayer side), Ar is preferably a heteroaryl group having 5 to 50 ringatoms in view of emission efficiency and lifetime, and preferably anaryl group having 6 to 50 ring carbon atoms in view of low voltage driveand lifetime. When the compound of the invention is used as a materialfor a first hole transporting layer, Ar is preferably a heteroaryl grouphaving 5 to 50 ring atoms and more preferably a group represented by anyof formulae (h), (i″) and (j″) described below, in view of emissionefficiency and lifetime.

In an embodiment of the invention, in view of low voltage drive,emission efficiency and lifetime, Ar is preferably a group representedby any of formulae (a) to (k), more preferably a group represented byany of formulae (b), (c), and (f) to (j), and still more preferably agroup represented by any of formulae (b), (c), (f), (h), and (j):

In formulae (a) to (k), R, R^(a), and R^(b) and preferred examplesthereof are each independently the same as those described with respectto R¹ in formula (1), and each R represents a substituent which isbonded to a carbon atom of each benzene ring in formulae (a) to (k).

R^(a) and R^(b) in formula (f) are each preferably one selected from thegroup consisting of a hydrogen atom, a substituted or unsubstitutedalkyl group having 1 to 20, preferably 1 to 8, and more preferably 1 to3 carbon atoms, and a substituted or unsubstituted aryl group having 6to 50, preferably 6 to 25, more preferably 6 to 18, and still morepreferably 6 to 12 ring carbon atoms; more preferably a group selectedfrom the group consisting of a substituted or unsubstituted alkyl grouphaving 1 to 20, preferably 1 to 8, and more preferably 1 to 3 carbonatoms and a substituted or unsubstituted aryl group having 6 to 50,preferably 6 to 25, more preferably 6 to 18, and still more preferably 6to 12 ring carbon atoms; and further preferably a substituted orunsubstituted alkyl group having 1 to 20, preferably 1 to 8, and morepreferably 1 to 3 carbon atoms.

R^(c) is a hydrogen atom, a substituted or unsubstituted alkyl grouphaving 1 to 20 carbon atoms, a substituted or unsubstituted aryl grouphaving 6 to 50 ring carbon atoms, or a substituted or unsubstitutedheteroaryl group having 5 to 50 ring atoms. These groups are the same asthose described with respect to R¹. Of the above, R^(c) is preferably asubstituted or unsubstituted alkyl group having 1 to 20 carbon atoms ora substituted or unsubstituted aryl group having 6 to 50 ring carbonatoms and more preferably a substituted or unsubstituted aryl grouphaving 6 to 50 ring carbon atoms.

When more than one R occurs, groups R may be the same or different, andtwo selected from groups R may be bonded to each other to form a ringstructure.

In formula (f), two selected from groups R, R^(a), and R^(b) may bebonded to each other to form a ring structure, but preferably not bondedto each other, thereby failing to form a ring structure.

In formulae (a) to (k), each k independently represents an integer of 0to 5, preferably an integer of 0 to 2, more preferably 0 or 1, and stillmore preferably 0.

Each m independently represents an integer of 0 to 4, preferably aninteger of 0 to 2, more preferably 0 or 1, and still more preferably 0.

Each n independently represents an integer of 0 to 3, preferably aninteger of 0 to 2, more preferably 0 or 1, and still more preferably 0

When k, m, and n are each 0, each benzene ring has no substituent.

* represents a bonding site to L² or the nitrogen atom.

In view of emission efficiency and lifetime, the group represented byformula (i) is preferably represented by formula (i′) or (i″) and morepreferably represented by formula (i″):

In view of emission efficiency and lifetime, the group represented byformula (j) is preferably represented by formula (j′) or (j″) and morepreferably represented by formula (j″):

In an embodiment of the invention, of the above groups for Ar, the grouprepresented by formula (b) is preferably represented by formula (b-1) or(b-2) in view of low voltage drive, emission efficiency and lifetime,the group represented by formula (c) is preferably represented byformula (c-1) or (c-2) in view of low voltage drive, emission efficiencyand lifetime, and the group represented by formula (d) is preferablyrepresented by formula (d-1) in view of low voltage drive, emissionefficiency and lifetime:

wherein R, k, m, n, and * are as defined in formulae (a) to (k).

In an embodiment of the invention, in view of low voltage drive,emission efficiency and lifetime, the group represented by formula (f)for Ar is preferably represented by formula (f-1) or (f-2) and morepreferably a group represented by formula (f-2):

wherein R, k, m, n, and * are as defined in formulae (a) to (k).

In formula (f-1) or (f-2), when more than one R occurs, groups R may bethe same or different, and two selected from groups R may be bonded toeach other to form a ring structure. The group represented by formula(f-1) wherein a ring structure is formed may include the following grouprepresented by formula (f-3), but preferably groups R are not bonded toeach other, thereby failing to form a ring structure:

wherein R, m, n, and * are as defined in formulae (a) to (j).

Ar in Formula (B1)

In formula (B1), Ar represents a substituted or unsubstituted aryl grouphaving 6 to 50, preferably 6 to 25, more preferably 6 to 18, and stillmore preferably 6 to 12 ring carbon atoms or a substituted orunsubstituted heteroaryl group having 5 to 50, preferably 5 to 10, morepreferably 5 to 8, and still more preferably 5 or 6 ring atoms.

Examples of the aryl group having 6 to 50 ring carbon atoms and theheteroaryl group having 5 to 50 ring atoms are the same as thosedescribed above with respect to R¹ to R⁸.

In view of low voltage drive, emission efficiency and lifetime, Ar informula (B1) is preferably a group represented by any of formulae (a) to(d) and (f) to (j):

wherein each R is the same as defined with respect to R¹ in formula(B1), when more than one R occurs, groups R may be the same ordifferent, and two selected from groups R may be bonded to each other toform a ring structure;

R^(a) and R^(b) in formula (f) each independently represent a hydrogenatom, a substituted or unsubstituted alkyl group having 1 to 20 carbonatoms, a substituted or unsubstituted aryl group having 6 to 50 ringcarbon atoms, a substituted or unsubstituted heteroaryl group having 5to 50 ring atoms, a halogen atom, a substituted or unsubstitutedfluoroalkyl group having 1 to 20 carbon atoms, a substituted orunsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted orunsubstituted fluoroalkoxy group having 1 to 20 carbon atoms, asubstituted or unsubstituted aryloxy group having 6 to 50 ring carbonatoms, or a cyano group, and two selected from groups R, R^(a), andR^(b) in formula (f) may be bonded to each other to form a ringstructure;

each k independently represents an integer of 0 to 5, each mindependently represents an integer of 0 to 4, and each n independentlyrepresents an integer of 0 to 3; and

* represents a bonding site to L² or the nitrogen atom in formula (B1).

The details of each group in formulae (a) to (d) and (f) to (j) are thesame as those described with respect to Ar in formula (A1).

In view of low voltage drive, emission efficiency and lifetime, of theabove groups for Ar in formula (B1), the group represented by formula(b) is preferably a group represented by formula (b-1) or (b-2), thegroup represented by formula (c) is preferably a group represented byformula (c-1) or (c-2), and the group represented by formula (d) ispreferably represented by formula (d-1):

wherein R, k, m, n, and * are as defined in formulae (a) to (d) and (f)to (j).

In an embodiment of the invention, Ar is preferably a group selectedfrom the following groups:

wherein * is as defined in formulae (a) to (d) and (f) to (j).

Also, in an embodiment of the invention, the group represented byformula (e) for Ar is preferably a group represented by formula (e-1):

wherein R, k, m, n, and * are as defined in formulae (a) to (d) and (f)to (j).

In formula (e-1), when more than one R occurs, groups R may be the sameor different, and two selected from groups R may be bonded to each otherto form a ring structure. The group represented by formula (e-1) whereina ring structure is formed may include the following group representedby formula (e-2), but preferably two selected from groups R are notbonded to each other, thereby failing to form a ring structure:

wherein R, m, n, and * are as defined in formulae (a) to (d) and (f) to(j).

In formulae (A1) and (B1), -L²-Ar is preferably a group represented byany of the following groups, wherein * is a bonding site to the nitrogenatom and R^(c) is the same as R^(c) in formula (k):

Compound in an Aspect of the Invention

The compound in an aspect of the invention is preferably a compoundrepresented by formula (A1-1) (also referred to as “compound (A1-1)”):

wherein R¹ to R⁸, n1, m2, k3, k4, n5, m6, L¹, L², and Ar are as definedin formula (A1).

The compound in another embodiment of the invention is preferably acompound represented by formula (A1-2) (also referred to as “compound(A1-2)”):

wherein R¹ to R⁸, n1, m2, k3, k4, n5, m6, L⁰ to L², and Ar are asdefined in formula (A1).

Of the compound (A1-2) in an embodiment of the invention, a compoundrepresented by formula (A1-2-1) (also referred to as “compound(A1-2-1)”) is more preferred:

wherein R¹ to R⁸, n1, m2, k3, k4, n5, m6, L², and Ar are as defined informula (A1).

The compound in another embodiment of the invention is preferably acompound represented by formula (A1-3) (also referred to as “compound(A1-3)”):

wherein R¹, R², R⁵, R⁶, n1, m2, n5, m6, L⁰ to L², and Ar are as definedin formula (A1)

The compound in another embodiment of the invention is preferably acompound represented by formula (A1-4) (also referred to as “compound(A1-4)”):

wherein L⁰ to L², and Ar are as defined in formula (A1).

The compound in another embodiment of the invention is preferably acompound represented by formula (B1-1) (also referred to as “compound(B1-1)”):

wherein R¹ to R⁸, n1, m2, k3, k4, n5, m6, L¹, L², and Ar are as definedin formula (B1).

As describe above, particularly L¹ in formula (B1-1) is preferably asubstituted or unsubstituted arylene group having 6 to 50, preferably 6to 24, and more preferably 6 to 12 ring carbon atoms or a substituted orunsubstituted heteroarylene group having 5 to 50, preferably 5 to 10,more preferably 5 to 8, and still more preferably 5 or 6 ring atoms, andmore preferably a substituted or unsubstituted arylene group having 6 to50, preferably 6 to 24, and more preferably 6 to 12 ring carbon atoms.

The compound in another embodiment of the invention may be a compoundrepresented by formula (B1-2) (also referred to as “compound (B1-2)”):

wherein R¹ to R⁸, n1, m2, k3, k4, n5, m6, L², and Ar are as defined informula (B1).

The compound in another embodiment of the invention is preferably acompound represented by formula (B1-3) (also referred to as “compound(B1-3)”):

wherein R¹, R², R⁵, R⁶, n1, m2, n5, m6, L⁰ to L², and Ar are as definedin formula (B1)

The compound in another embodiment of the invention is preferably acompound represented by formula (B1-4) (also referred to as “compound(B1-4)”):

wherein L⁰ to L², and Ar are as defined in formula (B1).

Examples of the compound (A1) in an aspect of the invention are shownbelow, although not limited thereto.

Of the above, the compound (A1) is preferably a compound selected fromthe following compounds:

Examples of the compound (B1) in an aspect of the invention are shownbelow, although not limited thereto.

Of the above, the compound (B1) is preferably a compound selected fromthe following compounds:

Material for Organic EL Devices

The material for organic EL devices in an aspect of the inventioncomprises the compound (1), i.e., at least one selected from thecompound (A1) and (B1), preferably comprises a compound selected fromthe compounds (A1-1) to (A1-6) and (A1-2-1), or preferably comprises acompound selected from the compounds (B1-1) to (B1-4). The followingdescription with respect to the compound (1) is equally applicable tothe compounds (A1-1) to (A1-6) and (A1-2-1) and the compound (B1-1) to(B1-4).

The material for organic EL devices in an aspect of the invention isuseful as a material for producing an organic EL device, for example, asa material for at least one organic thin film layer disposed between ananode and a cathode, particularly as a material for a hole transportinglayer or a hole injecting layer.

When the hole transporting is made into a two-layered structure of afirst hole transporting (anode side) and a second hole transportinglayer (cathode side), the material for organic EL devices comprisng thecompound (1) in an aspect of the invention is useful as a material foreither of the first hole transporting layer and the second holetransporting layer.

Organic EL Device

The organic EL device in an aspect of the invention will be describedbelow.

Representative device structures (1) to (13) are shown below, althoughnot limited thereto. The device structure (8) is preferably used.

-   (1) anode/light emitting layer/cathode;-   (2) anode/hole injecting layer/light emitting layer/cathode;-   (3) anode/light emitting layer/electron injecting layer/cathode;-   (4) anode/hole injecting layer/light emitting layer/electron    injecting layer/cathode;-   (5) anode/organic semiconductor layer/light emitting layer/cathode;-   (6) anode/organic semiconductor layer/electron blocking layer/light    emitting layer/cathode;-   (7) anode/organic semiconductor layer/light emitting layer/adhesion    improving layer/cathode;-   (8) anode/hole injecting layer/hole transporting layer/light    emitting layer/(electron transporting layer/) electron injecting    layer/cathode;-   (9) anode/insulating layer/light emitting layer/insulating    layer/cathode;-   (10) anode/inorganic semiconductor layer/insulating layer/light    emitting layer/insulating layer/cathode;-   (11) anode/organic semiconductor layer/insulating layer/light    emitting layer/insulating layer/cathode;-   (12) anode/insulating layer/hole injecting layer/hole transporting    layer/light emitting layer/insulating layer/cathode; and-   (13) anode/insulating layer/hole injecting layer/hole transporting    layer/light emitting layer/(electron transporting layer/) electron    injecting layer/cathode.

A schematic structure of an example of the organic EL device in anaspect of the invention is shown in FIG. 1, wherein the organic ELdevice 1 comprises a substrate 2, an anode 3, a cathode 4, and anemission unit 10 disposed between the anode 3 and the cathode 4. Theemission unit 10 comprises a light emitting layer 5 which comprises ahost material and a dopant (light emitting material). A holeinjecting/transporting layer (anode-side organic thin film layer) 6,etc. may be disposed between the light emitting layer 5 and the anode 3,and an electron injecting/transporting layer (cathode-side organic thinfilm layer) 7, etc. may be disposed between the light emitting layer 5and the cathode 4. An electron blocking layer may be disposed on theanode 3 side of the light emitting layer 5, and a hole blocking layermay be disposed on the cathode 4 side of the light emitting layer 5.With these blocking layers, electrons and holes are confined in thelight emitting layer 5 to increase the exciton generation in the lightemitting layer 5.

The organic EL device in an aspect of the invention comprises an anode,a cathode, and at least one organic thin film layer between the cathodeand the anode. The at least one organic thin film layer comprises alight emitting layer and at least one layer of the at least one organicthin film layer comprises the compound (1) represented by formula (A1)or (B1).

Examples of the organic thin film layer comprising the compound (1)include an anode-side organic thin film layer formed between an anodeand a light emitting layer (hole transporting layer, hole injectinglayer, etc.), a light emitting layer, a cathode-side organic thin filmlayer formed between a cathode and a light emitting layer (electrontransporting layer, electron injecting layer, etc.), a space layer, anda blocking layer, although not limited thereto.

The compound (1) may be used in any of the organic thin film layers ofan organic EL device. In view of driving at a lower voltage, thecompound (1) is preferably used in a hole injecting layer or a holetransporting layer, more preferably used in a hole transporting layer.

Namely, the organic EL device in an aspect of the invention is morepreferably an organic EL device wherein the at least one organic thinfilm layer comprises a hole injecting layer comprising the compound (1),a hole transporting layer comprising the compound (1), or both layers.

The content of the compound (1) in the organic thin film layer,preferably in a hole injecting layer or a hole transporting layer, ispreferably 30 to 100 mol %, more preferably 50 to 100 mol %, still morepreferably 80 to 100 mol %, and further preferably 95 to 100 mol % eachbased on the total molar amount of the components in the organic thinfilm layer.

Substrate

The substrate is a support for the emitting device and made of, forexample, glass, quartz, and plastics. The substrate may be a flexiblesubstrate, for example, a plastic substrate made of, for example,polycarbonate, polyarylate, polyether sulfone, polypropylene, polyester,polyvinyl fluoride, and polyvinyl chloride. An inorganic deposition filmis also usable.

Anode

The anode is formed on the substrate preferably from a metal, an alloy,an electrically conductive compound, and a mixture thereof, each havinga large work function, for example, 4.5 eV or more. Examples of thematerial for the anode include indium oxide-tin oxide (ITO: indium tinoxide), indium oxide-tin oxide doped with silicon or silicon oxide,indium oxide-zinc oxide, indium oxide doped with tungsten oxide and zincoxide, and graphene. In addition, gold (Au), platinum (Pt), nickel (Ni),tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co),copper (Cu), palladium (Pd), titanium (Ti), and a metal nitride (forexample, titanium nitride) are also usable.

These materials are made into a film generally by a sputtering method.For example, a film of indium oxide-zinc oxide is formed by sputteringan indium oxide target doped with 1 to 10% by mass of zinc oxide, and afilm of indium oxide doped with tungsten oxide and zinc oxide is formedby sputtering an indium oxide target doped with 0.5 to 5% by mass oftungsten oxide and 0.1 to 1% by mass of zinc oxide. In addition, avacuum vapor deposition method, a coating method, an inkjet method, anda spin coating method are usable.

A hole injecting layer to be formed in contact with the anode is formedfrom a composite material which is capable of easily injecting holesindependently of the work function of the anode. Therefore a material,for example, a metal, an alloy, an electroconductive compound, a mixturethereof, and a group 1 element and a group 2 element of the periodictable are usable as the electrode material.

A material having a small work function, for example, the group 1element and the group 2 element of the periodic table, i.e., an alkalimetal, such as lithium (Li) and cesium (Cs), an alkaline earth metal,such as magnesium (Mg), calcium (Ca), and strontium (Sr), and an alloythereof, such as MgAg and AlLi, are also usable. In addition, a rareearth metal, such as europium (Eu) and ytterbium (Yb), and an alloythereof are also usable. The alkali metal, the alkaline earth metal, andthe alloy thereof can be made into the anode by a vacuum vapordeposition or a sputtering method. When a silver paste, etc. is used, acoating method and an inkjet method are usable.

Hole Injecting Layer

The hole injecting layer comprises a highly hole-transporting material.

The hole injecting layer of the organic EL device in an aspect of theinvention preferably comprises the compound (1) in an aspect of theinvention. In addition, the hole injecting layer of the organic ELdevice in an aspect of the invention may comprise the compound (1) aloneor may comprise the compound (1) in combination with the followingcompound.

Examples of the highly hole-transporting material include molybdenumoxide, titanium oxide, vanadium oxide, rhenium oxide, ruthenium oxide,chromium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silveroxide, tungsten oxide, and manganese oxide.

The following low molecular aromatic amine compound is also usable:4,4′,4″-tris(N,N-diphenylamino)triphenylamine (TDATA),4,4′,4″-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (MTDATA),4,4′-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (DPAB),4,4′-bis(N-{4-[N′-(3-methylphenyl)-N′-phenylamino]phenyl}-N-phenylamino)biphenyl(DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene(DPA3B), 3-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole(PCzPCA1),3,6-bis[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole(PCzPCA2), and3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-yl)amino]-9-phenylcarbazole(PCzPCN1).

A polymeric compound, such as an oligomer, a dendrimer, a polymer, isalso usable. Examples thereof include poly(N-vinylcarbazole) (PVK),poly(4-vinyltriphenylamine) (PVTPA),poly[N-(4-{N′-[4-(4-diphenylamino)phenyl]phenyl-N′-phenylamino}phenyl)methacrylamide](PTPDMA), and poly[N,N′-bis(4-butylphenyl)-N,N′-bis(phenyl)benzidine](Poly-TPD). An acid-added polymeric compound, such aspoly(3,4-ethylenedioxythiophene)/poly(styrenesulfonic acid) (PEDOT/PSS)and polyalinine/poly(styrenesulfonic acid) (PAni/PSS), is also usable.

Hole Transporting Layer

The hole transporting layer comprises a highly hole-transportingmaterial.

The hole transporting layer of the organic EL device in an aspect of theinvention preferably comprises the compound (1) in an aspect of theinvention. In addition, the hole transporting layer of the organic ELdevice in an aspect of the invention may comprise the compound (1) aloneor may comprise the compound (1) in combination with the followingcompound.

The hole transporting layer may comprise an aromatic amine compound, acarbazole derivative, an anthracene derivative, etc. The aromatic aminecompound has preferably 30 to 100 and more preferably 40 to 80 ringcarbon atom in total of the aromatic rings and is preferably an aromaticmonoamine compound or an aromatic diamine compound. The aromatic aminecompound may have a heteroaryl group having preferably 5 to 50 and morepreferably 5 to 20 ring atoms, for example, a dibenzofuranyl group and adibenzothiophenyl group.

Examples the aromatic amine compound include4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB),N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1′-biphenyl]-4,4′-diamine(TPD), 4-phenyl-4′-(9-phenylfluorene-9-yl)triphenylamine (BAFLP),4,4′-bis[N-(9,9-dimethylfluorene-2-yl)-N-phenylamino]biphenyl (DFLDPBi),4,4′,4″-tris(N,N-diphenylamino)triphenylamine (TDATA),4,4′,4″-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (MTDATA),and 4,4′-bis[N-(spiro-9,9′-bifluorene-2-yl)-N-phenylamino]biphenyl(BSPB). The above compounds have a hole mobility of mainly 10⁻⁶ cm²/Vsor more.

In addition, the hole transporting layer may contain a carbazolederivative, such as CBP, CzPA, and PCzPA, an anthracene derivative, suchas t-BuDNA, DNA, and DPAnth, and a polymeric compound, such aspoly(N-vinylcarbazole) (PVK) and poly(4-vinyltriphenylamine) (PVTPA).

Other materials are also usable if their hole transporting ability ishigher than their electron transporting ability. The layer comprising ahighly hole-transporting material may be a single layer or a laminate oftwo or more layers each comprising the material mentioned above. Forexample, the hole transporting layer may be made into a two-layeredstructure of a first hole transporting layer (anode side) and a secondhole transporting layer (light emitting layer side). In such atwo-layered structure, the compound (1) in an aspect of the inventionmay be used in either of the first hole transporting layer and thesecond hole transporting layer. Although not particularly limited, whenthe compound (1) in an aspect of the invention is used in the first holetransporting layer, the second hole transporting layer preferablycomprises the above aromatic monoamine compound, and when the compound(1) in an aspect of the invention is used in the second holetransporting layer, the first hole transporting layer preferablycomprises the above aromatic diamine compound.

In the organic EL device in an aspect of the invention, a layercomprising an electron-accepting compound (acceptor material) may beformed on the anode-side of the hole transporting layer or the firsthole transporting layer, because it is expected that the driving voltageis lowered and the production cost is reduced.

A compound represented by formula (A) is preferably used as the acceptorcompound:

wherein R³¹¹ to R³¹⁶ may be the same or different and each independentlyrepresent a cyano group, —CONH₂, a carboxyl group, or —COOR³¹⁷ whereinR³¹⁷ represents an alkyl group having 1 to 20 carbon atoms or acycloalkyl group having 3 to 20 carbon atoms; and R³¹¹ and R³¹², R³¹³and R³¹⁴, or R³¹⁵ and R³¹⁶ may be bonded to each other to form a grouprepresented by —CO—O—CO—.

Examples of alkyl group for R³¹⁷ include a methyl group, an ethyl group,a n-propyl group, an isopropyl group, a n-butyl group, an isobutylgroup, and a t-butyl group. Examples of cycloalkyl group include acyclopentyl group and a cyclohexyl group.

The thickness of the layer comprising the acceptor compound ispreferably 5 to 20 nm, although not particularly limited thereto.

Guest Material of Light Emitting Layer

The light emitting layer comprises a highly light-emitting material andmay be formed from a various kind of materials. For example, afluorescent emitting compound and a phosphorescent emitting compound areusable as the highly light-emitting material. The fluorescent emittingcompound is a compound capable of emitting light from a singlet excitedstate, and the phosphorescent emitting compound is a compound capable ofemitting light from a triplet excited state.

Examples of blue fluorescent emitting material for use in the lightemitting layer include a pyrene derivative, a styrylamine derivative, achrysene derivative, a fluoranthene derivative, a fluorene derivative, adiamine derivative, and a triarylamine derivative, such asN,N′-bis[4-(9H-carbazole-9-yl)phenyl]-N,N′-diphenylstilbene-4,4′-diamine(YGA2S), 4-(9H-carbazole-9-yl)-4′-(10-phenyl-9-anthryl)triphenylamine(YGAPA), and4-(10-phenyl-9-anthryl)-4′-(9-phenyl-9H-carbazole-3-yl)triphenylamine(PCBAPA).

Examples of green fluorescent emitting material for use in the lightemitting layer include an aromatic amine derivative, such asN-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazole-3-amine (2PCAPA),N-[9,10-bis(1,1′-biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazole-3-amine(2PCABPhA),N-(9,10-diphenyl-2-anthryl)-N,N′,N′-triphenyl-1,4-phenylenediamine(2DPAPA),N-[9,10-bis(1,1′-biphenyl-2-yl)-2-anthryl]-N,N′,N′-triphenyl-1,4-phenylenediamine(2DPABPhA),N-[9,10-bis(1,1′-biphenyl-2-yl)]-N-[4-(9H-carbazole-9-yl)phenyl]-N-phenylanthracene-2-amine(2YGABPhA), and N,N,9-triphenylanthracene-9-amine (DPhAPhA).

Examples of red fluorescent emitting material for use in the lightemitting layer include a tetracene derivative and a diamine derivative,such as N,N,N′,N′-tetrakis(4-methylphenyl)tetracene-5,11-diamine(p-mPhTD) and7,14-diphenyl-N,N,N′,N′-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine(p-mPhAFD).

Examples of blue phosphorescent emitting material for use in the lightemitting layer include a metal complex, such as an iridium complex, anosmium complex, and a platinum complex. Examples thereof includebis[2-(4′,6′-difluorophenyl)pyridinato-N,C2]iridium(III)tetrakis(1-pyrazolyl)borato (FIr₆),bis[2-(4′,6′-difluorophenyl)pyridinato-N,C2]iridium(III) picolinato(FIrpic), bis[2-(3′,5′-bistrifluoromethylphenyl)pyridinato-N,C2′]iridium (III) picolinato (Ir(CF₃ppy)₂(pic)), andbis[2-(4′,6′-difluorophenyl)pyridinato-N,C2′]iridium (III)acetylacetonato (FIracac).

Examples of green phosphorescent emitting material for use in the lightemitting layer include an iridium complex, such astris(2-phenylpyridinato-N,C2′)iridium(III) (Ir(ppy)₃),bis(2-phenylpyridinato-N,C2′)iridium(III) acetylacetonato(Ir(ppy)₂(acac)), bis(1,2-diphenyl-1H-benzimidazolato)iridium(III)acetylacetonato (Ir(pbi)₂(acac)), andbis(benzo[h]quinolinato)iridium(III) acetylacetonato (Ir(bzq)₂(acac)).

Examples of red phosphorescent emitting material for use in the lightemitting layer include a metal complex, such as an iridium complex, aplatinum complex, a terbium complex, and a europium complex. Examplesthereof include an organometallic complex, such asbis[2-(2′-benzo[4,5-α]thienyl)pyridinato-N,C3′]iridium(III)acetylacetonato (Ir(btp)₂(acac)),bis(1-phenylisoquinolinato-N,C2′)iridium(III) acetylacetonato(Ir(piq)₂(acac)), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (Ir(Fdpq)₂(acac)),and 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II)(PtOEP).

The following rare earth metal complex, such as tris(acetylacetonato)(monophenanthroline)terbium(III) (Tb(acac)₃(Phen)),tris(1,3-thphenyl-1,3-propanedionato)(monophenanthroline)europium (III)(Eu(DBM)₃(Phen)), and tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III)(Eu(TTA)₃(Phen)), emits light from the rare earth metal ion (electrontransition between different multiple states), and therefore, usable asa phosphorescent emitting compound.

Host Material for Light Emitting Layer

The light emitting layer may be formed by dispersing the highlylight-emitting material (guest material) mentioned above in anothermaterial (host material). The material in which the highlylight-emitting material is to be dispersed may be selected from variouskinds of materials and is preferably a material having a lowestunoccupied molecular orbital level (LUMO level) higher than that of thehighly light-emitting material and a highest occupied molecular orbitallevel (HOMO level) lower than that of the highly light-emittingmaterial.

The material in which the highly light-emitting material is to bedispersed may include, for example,

-   (1) a metal complex, such as an aluminum complex, a beryllium    complex, and a zinc complex;-   (2) a heterocyclic compound, such as an oxadiazole derivative, a    benzimidazole derivative, and a phenanthroline derivative;-   (3) a fused aromatic compound, such as a carbazole derivative, an    anthracene derivative, a phenanthrene derivative, a pyrene    derivative, and a chrysene derivative; and-   (4) an aromatic amine compound, such as a triarylamine derivative    and a fused aromatic polycyclic amine derivative.

Examples thereof include:

a metal complex, such as tris(8-quinolinolato)aluminum(III) (Alq),tris(4-methyl-8-quinolinolato)aluminum(III) (Almq₃),bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (BeBq₂),bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (BAlq),bis(8-quinolinolato)zinc(II) (Znq),bis[2-(2-benzoxazolyl)phenolato]zinc(II) (ZnPBO), andbis[2-(2-benzothiazolyl)phenolato]zinc(II) (ZnBTZ);

a heterocyclic compound, such as2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD),1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (OXD-7),3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (TAZ),2,2′,2″-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (TPBI),bathophenanthroline (BPhen), and bathocuproin (BCP);

a fused aromatic compound, such as9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (CzPA),3,6-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (DPCzPA),9,10-bis(3,5-diphenylphenyl)anthracene (DPPA),9,10-di(2-naphthyl)anthracene (DNA),2-tert-butyl-9,10-di(2-naphthyl)anthracene (t-BuDNA), 9,9′-bianthryl(BANT), 9,9′-(stilbene-3,3′-diyl)diphenanthrene (DPNS),9,9′-(stilbene-4,4′-diyl)diphenanthrene (DPNS2),3,3′,3″-(benzene-1,3,5-triyl)tripyrene (TPB3), 9,10-diphenylanthracene(DPAnth), and 6,12-dimethoxy-5,11-diphenylchrysene; and

an aromatic amine compound, such asN,N-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole-3-amine(CzA1PA), 4-(10-phenyl-9-anthryl)triphenylamine (DPhPA),N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole-3-amine(PCAPA),N,9-diphenyl-N-{4-[4-(10-phenyl-9-anthryl)phenyl]phenyl}-9H-carbazole-3-amine(PCAPBA), N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazole-3-amine(2PCAPA), NPB (or α-NPD), TPD, DFLDPBi, and BSPB.

The material (host material) for dispersing the highly light-emittingmaterial (guest material) may be used alone or in combination of two ormore.

Electron Transporting Layer

The electron transporting layer comprises a highly electron-transportingmaterial, for example,

-   (1) a metal complex, such as an aluminum complex, a beryllium    complex, and a zinc complex;-   (2) a heteroaromatic compound, such as an imidazole derivative, a    benzimidazole derivative, an azine derivative, a carbazole    derivative, and a phenanthroline derivative; and-   (3) a polymeric compound.

Examples of the low molecular organic compound include a metal complex,such as Alq, tris(4-methyl-8-quinolinolato)aluminum (Almq3),bis(10-hydroxybenzo[h]quinolinato)beryllium (BeBq₂), BAlq, Znq, ZnPBO,and ZnBTZ; and a heteroaromatic compound, such as2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD),1,3-bis[5-(ptert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (OXD-7),3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenylyl)-1,2,4-triazole (TAZ),3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenylyl)-1,2,4-triazole(p-EtTAZ), bathophenanthroline (BPhen), bathocuproine (BCP), and4,4′-bis(5-methylbenzoxazole-2-yl)stilbene (BzOs).

The above compounds have an electron mobility of mainly 10⁻⁶ cm²/Vs ormore. Other materials are also usable in the electron transporting layerif their electron transporting ability is higher than their holetransporting ability. The electron transporting layer may be a singlelayer or a laminate of two or more layers each comprising the materialmentioned above.

A polymeric compound is also usable in the electron transporting layer.Examples thereof includepoly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (PF-Py), andpoly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2′-bipyridine-6,6′-diyl)](PF-BPy).

Electron Injecting Layer

The electron injecting layer comprises a highly electron-injectingmaterial, for example, an alkali metal, an alkaline earth metal, and acompound of these metals, such as lithium (Li), cesium (Cs), calcium(Ca), lithium fluoride (LiF), cesium fluoride (CsF), calciumfluoride(CaF2), and lithium oxide (LiOx). In addition, an electrontransporting material which is incorporated with an alkali metal, analkaline earth metal or a compound thereof, for example, Alq doped withmagnesium (Mg), is also usable. By using such a material, electrons areefficiently injected from the cathode.

A composite material obtained by mixing an organic compound and anelectron donor is also usable in the electron injecting layer. Such acomposite material is excellent in the electron injecting ability andthe electron transporting ability, because the electron donor donateselectrons to the organic compound. The organic compound is preferably amaterial excellent in transporting the received electrons. Examplesthereof are the materials for the electron transporting layer mentionedabove, such as the metal complex and the aromatic heterocyclic compound.Any material capable of giving its electron to another organic compoundis usable as the electron donor. Preferred examples thereof are analkali metal, an alkaline earth metal, and a rare earth metal, such aslithium, cesium, magnesium, calcium, erbium, and ytterbium; an alkalimetal oxide and an alkaline earth metal oxide, such as, lithium oxide,calcium oxide, and barium oxide; a Lewis base, such as magnesium oxide;and an organic compound, such as tetrathiafulvalene (TTF).

Cathode

The cathode is formed preferably from a metal, an alloy, an electricallyconductive compound, and a mixture thereof, each having a small workfunction, for example, a work function of 3.8 eV or less. Examples ofthe material for the cathode include a metal of the group 1 or 2 of theperiodic table, for example, an alkali metal, such as lithium (Li) andcesium (Cs), an alkaline earth metal, such as magnesium (Mg), an alloycontaining these metals (for example, MgAg and AlLi), a rare earthmetal, such as europium (Eu) and ytterbium (Yb), and an alloy containinga rare earth metal.

The alkali metal, the alkaline earth metal, and the alloy thereof can bemade into the cathode by a vacuum vapor deposition or a sputteringmethod. When a silver paste, etc. is used, a coating method and aninkjet method are usable.

When the electron injecting layer is formed, the material for thecathode can be selected independently from the work function and variouselectroconductive materials, such as Al, Ag, ITO, graphene, and indiumoxide-tin oxide doped with silicon or silicon oxide, are usable. Theseelectroconductive materials are made into films by a sputtering method,an inkjet method, and a spin coating method.

Each layer of the organic EL device is formed by a dry film-formingmethod, such as vacuum vapor deposition, sputtering, plasma, and ionplating, and a wet film-forming method, such as spin coating, dipcoating, and flow coating.

In the wet film-forming method, the material for each layer is dissolvedor dispersed in a suitable solvent, such as ethanol, chloroform,tetrahydrofuran, and dioxane, and then the obtained solution ordispersion is made into a film. To improve the film-forming propertiesand prevent pin holes on the film, the solution and the dispersion mayinclude a resin or an additive. Examples of the resin include aninsulating resin and a copolymer thereof, such as polystyrene,polycarbonate, polyarylate, polyester, polyamide, polyurethane,polysulfone, polymethyl methacrylate, polymethyl acrylate, andcellulose; and a photoconductive resin, such as poly-N-vinylcarbazoleand polysilane; and an electroconductive resin, such as polythiopheneand polypyrrole. Examples of the additive include an antioxidant, anultraviolet absorber, and a plasticizer.

The thickness of each layer is not particularly limited and selected soas to obtain a good device performance. If extremely thick, a largeapplied voltage is needed to obtain a desired emission output, therebyreducing the efficiency. If extremely thin, pinholes occur on the filmto make it difficult to obtain a sufficient luminance even when applyingan electric field. The thickness is generally 5 nm to 10 μm andpreferably 10 nm to 0.2 μm.

The thickness of the light emitting layer is, but not particularlylimited to, preferably 5 to 100 nm, more preferably 7 to 70 nm, andstill more preferably 10 to 50 nm. The thickness of the holetransporting layer is preferably 10 to 300 nm. When the holetransporting layer is made into a two-layered structure as describedabove, the thickness of the first hole transporting layer is preferably50 to 300 nm, more preferably 50 to 250 nm, still more preferably 50 to200 nm, and further preferably 50 to 150 nm, and the thickness of thesecond hole transporting layer is preferably 5 to 100 nm, morepreferably 5 to 50 nm, still more preferably 5 to 30 nm, and furtherpreferably 5 to 20 nm, although not limited thereto.

Electronic Equipment

The electronic equipment in an aspect of the invention comprises theorganic EL device in an aspect of the invention mentioned above.

Examples of the electronic equipment include display parts, such asorganic EL panel module; display devices of television sets, mobilephones, personal computer, etc.; and light emitting sources of lightingequipment and vehicle lighting equipment.

EXAMPLES

The present invention will be described in more detail with reference tothe examples and comparative examples. However, it should be noted thatthe scope of the invention is not limited thereto.

The compounds recited in the claims of this application can besynthesized by referring to the following synthetic reactions whileusing a known synthetic reaction and a starting material in accordancewith the target compound.

Synthesis of Compound (A1) Intermediate Synthesis 1-1 (Synthesis ofIntermediate 1-1)

Under an argon atmosphere, into a mixture of 28.3 g (100.0 mmol) of4-iodobromobenzene, 22.3 g (105.0 mmol) of dibenzofuran-4-boronic acid,and 2.31 g (2.00 mmol) of Pd[PPh₃]₄, 150 ml of toluene, 150 ml ofdimethoxyethane, and 150 ml (300.0 mmol) of a 2 M aqueous solution ofNa₂CO₃ were added, and the resultant mixture was refluxed for 10 h underheating and stirring.

After the reaction, the reaction mixture was cooled to room temperatureand extracted with dichloromethane in a separating funnel. The organiclayer was dried over MgSO₄, filtered, and concentrated. The residualconcentrate was purified by column chromatography to obtain 26.2 g of awhite solid (yield; 81%), which was identified by FD-MS analysis (fielddesorption mass spectrometric analysis) as the intermediate 1-1.

Intermediate Synthesis 1-2 (Synthesis of Intermediate 1-2)

In the same manner as in Intermediate Synthesis 1-1 except for using22.3 g of dibenzofuran-2-boronic acid in place of dibenzofuran-4-boronicacid, 27.4 g of a white solid was obtained (yield: 85%), which wasidentified by FD-MS analysis as the following intermediate 1-2.

Intermediate Synthesis 1-3 (Synthesis of Intermediate 1-3)

Under an argon atmosphere, into a mixture of 28.3 g (100.0 mmol) of4-iodobromobenzene, 23.9 g (105.0 mmol) of dibenzothophene-4-boronicacid, and 2.31 g (2.00 mmol) of Pd[PPh₃]₄, 150 ml of toluene, 150 ml ofdimethoxyethane, and 150 ml (300.0 mmol) of a 2 M aqueous solution ofNa₂CO₃ were added, and the resultant mixture was refluxed for 10 h underheating and stirring.

After the reaction, the reaction mixture was cooled to room temperatureand extracted with dichloromethane in a separating funnel. The organiclayer was dried over MgSO₄, filtered, and concentrated. The residualconcentrate was purified by column chromatography to obtain 27.1 g of awhite solid (yield: 80%), which was identified by FD-MS analysis as thefollowing intermediate1-3.

Intermediate Synthesis 1-4 (Synthesis of Intermediate 1-4)

In the same manner as in Intermediate Synthesis 1-3 except for using23.9 g of dibenzothiophene-2-boronic acid in place ofdibenzothophene-4-boronic acid, 27.2 g of a white solid was obtained(yield: 80%), which was identified by FD-MS analysis as the followingintermediate 1-4.

Intermediate Synthesis 1-5 (Synthesis of Intermediate 1-5)

Under an argon atmosphere, into a mixture of 47.0 g (201.6 mmol) of4-bromobiphenyl, 23 g (90.6 mmol) of iodine, and 9.4 g (41.2 mmol) ofperiodic acid dihydrate, 42 ml of water, 360 ml of acetic acid, and 11ml of sulfuric acid were added, and the resultant mixture was stirred at65° C. for 30 min and further stirred at 90° C. for 6 h.

After the reaction, the reaction mixture was poured into iced water andfiltered. After washing with water and then methanol, 67 g of a whitepowder was obtained (yield: 93%), which was identified by FD-MS analysisas the following intermediate 1-5.

Intermediate Synthesis 1-6 (Synthesis of Intermediate 1-6)

Under an argon atmosphere, into a mixture of 35.9 g (100.0 mmol) of theintermediate 1-5, 16.7 g (100.0 mmol) of carbazole, 0.2 g (1.00 mmol) ofcopper iodide (CuI), and 42.4 g (210.0 mmol) of tripotassium phosphate,2 ml of trans-1,2-cyclohexane diamine and 300 ml of 1,4-dioxane wereadded, and the resultant mixture was stirred at 100° C. for 20 h.

After the reaction, the reaction mixture was liquid-liquid separatedafter adding 300 ml of water and then the aqueous layer was removed Theorganic layer was dried over sodium sulfate and then concentrated. Theobtained residue was purified by silica gel column chromatography toobtain 23.1 g of a white crystal (yield: 58%), which was identified byFD-MS analysis as the following intermediate 1-6.

Intermediate Synthesis A1-7 (Synthesis of Intermediate A1-7)

Under an argon atmosphere, into a mixture of 39.7 g (100.0 mmol) of3-bromo-9,9′-diphenylfluorene, 16.4 g (105.0 mmol) of4-chlorophenylboronic acid, and 2.31 g (2.00 mmol) of Pd[PPh₃]₄, 150 mlof toluene, 150 ml of dimethoxyethane, and 150 ml (300.0 mmol) of a 2 Maqueous solution of Na₂CO₃ were added, and the resultant mixture wasrefluxed for 10 h under heating and stirring.

After the reaction, the reaction mixture was cooled to room temperatureand extracted with dichloromethane in a separating funnel. The organiclayer was dried over MgSO₄, filtered, and concentrated. The residualconcentrate was purified by column chromatography to obtain 34.3 g of awhite solid (yield: 80%), which was identified by FD-MS analysis as thefollowing intermediate A1-7.

Intermediate Synthesis 1-8 (Synthesis of Intermediate (1-8))

Under an argon atmosphere, a mixture of 28.3 g (100.0 mmol) of4-iodobromobenzene, 30.1 g (105.0 mmol) of3-(9H-carbazole-9-yl)phenylboronic acid, and 2.31 g (2.00 mmol) ofPd[PPh₃]₄, 150 ml of toluene, 150 ml of dimethoxyethane, 150 ml (300.0mmol) of a 2 M aqueous solution of Na₂CO₃ were added, and the resultantmixture was refluxed for 10 h under heating and stirring.

After the reaction, the reaction mixture was cooled to room temperatureand extracted with dichloromethane in a separating funnel. The organiclayer was dried over MgSO₄, filtered, and concentrated. The residualconcentrate was purified by column chromatography to obtain 27.2 g of awhite solid (yield: 68%), which was identified by FD-MS analysis as thefollowing intermediate (1-8).

Intermediate Synthesis 1-9 (Synthesis of Intermediate (1-9))

In the same manner as in Intermediate Synthesis 1-8 except for using30.3 g of 3-(dibenzofuran-4-yl)phenylboronic acid in place of3-(9H-carbazole-9-yl)phenylboronic acid, 24.0 g of a white solid wasobtained (yield: 60%), which was identified by FD-MS analysis as thefollowing intermediate (1-9).

Intermediate Synthesis A2-1 (Synthesis of Intermediate A2-1)

Under an argon atmosphere, into a mixture of 19.9 g (50.0 mmol) of3-bromo-9,9′-diphenylfluorene, 10.5 g (50.0 mmol) of2-amino-9,9′-dimethylfluorene, and 9.6 g (100.0 mmol) of sodiumt-butoxide, 250 ml of dehydrated toluene was added, and the resultantmixture was stirred. After further adding 225 mg (1.0 mmol) of palladiumacetate and 202 mg (1.0 mmol) of tri-t-butylphosphine, the mixture wasallowed to react at 80° C. for 8 h.

After cooling, the reaction mixture was filtered through celite/silicagel, and the filtrate was concentrated under reduced pressure. Theobtained residue was recrystallized from toluene, and the crystalcollected by filtration was dried to obtain 17.1 g of a white crystal(yield: 65%), which was identified by FD-MS analysis as the followingintermediate A2-1.

Intermediate Synthesis A2-2 (Synthesis of Intermediate (A2-2))

Under an argon atmosphere, into a mixture of 17.2 g (100.0 mmol) of4-bromoaniline, 25.0 g (105.0 mmol) of 9,9′-dimethylfluorene-2-boronicacid, and 2.31 g (2.00 mmol) of Pd[PPh₃]₄, 150 ml of toluene, 150 ml ofdimethoxyethane, and 150 ml (300.0 mmol) of a 2 M aqueous solution ofNa₂CO₃ were added, and the resultant mixture was refluxed for 10 h underheating and stirring.

After the reaction, the reaction mixture was cooled to room temperatureand extracted with dichloromethane in a separating funnel. The organiclayer was dried over MgSO₄, filtered, and concentrated. The residualconcentrate was purified by column chromatography to obtain 11.4 g of awhite solid (yield: 40%), which was identified by FD-MS analysis as thefollowing intermediate A2-2.

Intermediate Synthesis A2-3 (Synthesis of Intermediate (A2-3))

Under an argon atmosphere, into a mixture of 19.9 g (50.0 mmol) of3-bromo-9,9′-diphenylfluorene, 14.3 g (50.0 mmol) of the intermediate(A2-2), and 9.6 g (100.0 mmol) of sodium t-butoxide, 250 ml ofdehydrated toluene was added, and the resultant mixture was stirred.After further adding 225 mg (1.0 mmol) of palladium acetate and 202 mg(1.0 mmol) of tri-t-butylphosphine, the mixture was allowed to react at80° C. for 8 h.

After cooling, the reaction mixture was filtered through celite/silicagel, and the filtrate was concentrated under reduced pressure. Theobtained residue was recrystallized from toluene, and the precipitatedcrystal was collected by filtration and dried to obtain 16.5 g of awhite solid (yield: 55%), which was identified by FD-MS analysis as thefollowing intermediate (A2-3).

Synthesis Example A1 Production of Compound (HA1)

Under an argon atmosphere, into a mixture of 2.3 g (10.0 mmol) of4-bromobiphenyl, 5.3 g (10.0 mmol) of the intermediate (A2-1), 0.14 g(0.15 mmol) of Pd₂(dba)₃, 0.087 g (0.3 mmol) of P(^(t)Bu)₃HBF₄, and 1.9g (20.0 mmol) of sodium t-butoxide, 50 ml of dehydrated xylene wasadded, and the resultant mixture was refluxed for 8 h under heating. Theterm “dba” used herein means dibenzylideneacetone, and the term “^(t)Bu”means tert-butyl.

After the reaction, the reaction mixture was cooled to 50° C. andfiltered through celite/silica gel. The filtrate was concentrated andthe residual concentrate was purified by column chromatography to obtaina white solid. The crude product was recrystallized from toluene toobtain 2.3 g of a white crystal (yield: 34%), which was identified byFD-MS analysis as the following compound (HA1).

Synthesis Example A2 Production of Compound (HA2)

In the same manner as in Synthesis Example A1 except for using 2.3 g of2-bromobiphenyl in place of 4-bromobiphenyl, 2.6 g of a white crystalwas obtained (yield: 38%), which was identified by FD-MS analysis as thefollowing compound (HA2).

Synthesis Example A3 Production of Compound (HA3)

In the same manner as in Synthesis Example A1 except for using 2.7 g of2-bromo-9,9′-dimethylfluorene in place of 4-bromobiphenyl, 2.9 g of awhite crystal was obtained (yield: 40%), which was identified by FD-MSanalysis as the following compound (HA3).

Synthesis Example A4 Production of Compound (HA4)

In the same manner as in Synthesis Example A1 except for using 3.2 g ofthe intermediate (1-1) in place of 4-bromobiphenyl, 2.3 g of a whitecrystal was obtained (yield: 30%), which was identified by FD-MSanalysis as the following compound (HA4).

Synthesis Example A5 Production of Compound (HA5)

In the same manner as in Synthesis Example A1 except for using 3.2 g ofthe intermediate (1-2) in place of 4-bromobiphenyl, 2.5 g of a whitecrystal was obtained (yield: 33%), which was identified by FD-MSanalysis as the following compound (HA5).

Synthesis Example A6 Production of Compound (HA6)

In the same manner as in Synthesis Example A1 except for using 3.4 g ofthe intermediate (1-3) in place of 4-bromobiphenyl, 2.0 g of a whitecrystal was obtained (yield: 25%), which was identified by FD-MSanalysis as the following compound (HA6).

Synthesis Example A7 Production of Compound (HA7)

In the same manner as in Synthesis Example A1 except for using 3.4 g ofthe intermediate (1-4) in place of 4-bromobiphenyl, 2.0 g of a whitecrystal was obtained (yield: 25%), which was identified by FD-MSanalysis as the following compound (HA7).

Synthesis Example A8 Production of Compound (HA8)

In the same manner as in Synthesis Example A1 except for using 4.0 g ofthe intermediate (1-6) in place of 4-bromobiphenyl, 1.7 g of a whitecrystal was obtained (yield: 20%), which was identified by FD-MSanalysis as the following compound (HA8).

Synthesis Example A9 Production of Compound (HA9)

Under an argon atmosphere, into a mixture of 4.3 g (10.0 mmol) of theintermediate (A1-7), 3.6 g (10.0 mmol) ofN-(biphenyl-4-yl)-9,9′-dimethylfluorene-2-amine, 0.14 g (0.15 mmol) ofPd₂(dba)₃, 0.087 g (0.3 mmol) of P(^(t)Bu)₃HBF₄, and 1.9 g (20.0 mmol)of sodium t-butoxide, 50 ml of dehydrated xylene was added, and theresultant mixture was refluxed for 8 h under heating.

After the reaction, the reaction mixture was cooled to 50° C. andfiltered through celite/silica gel. The filtrate was concentrated andthe residual concentrate was purified by column chromatography to obtaina white solid. The crude product was recrystallized from toluene toobtain 2.6 g of a white crystal (yield: 35%), which was identified byFD-MS analysis as the following compound (HA9).

Synthesis Example A10 Production of Compound (HA10)

In the same manner as in Synthesis Example A9 except for using 3.6 g ofN-(biphenyl-2-yl)-9,9′-dimethylfluorene-2-amine in place ofN-(biphenyl-4-yl)-9,9′-dimethylfluorene-2-amine, 2.6 g of a whitecrystal was obtained (yield: 35%), which was identified by FD-MSanalysis as the following compound (HA10).

Synthesis Example A11 Production of Compound (HA11)

In the same manner as in Synthesis Example A9 except for using 4.0 g ofN,N-bis(9,9′-dimethylfluorene-2-yl)amine in place ofN-(biphenyl-4-yl)-9,9′-dimethylfluorene-2-amine, 2.1 g of a whitecrystal was obtained (yield: 27%), which was identified by FD-MSanalysis as the following compound (HA11).

Synthesis Example A12 Production of compound (HA12)

In the same manner as in Synthesis Example A1 except for using 3.1 g of4-bromoterphenyl in place of 4-bromobiphenyl, 2.6 g of a white crystalwas obtained (yield: 34%), which was identified by FD-MS analysis as thefollowing compound (HA12).

Synthesis Example A13 Production of Compound (HA13)

In the same manner as in Synthesis Example A1 except for using 3.1 g of2-bromotriphenylene in place of 4-bromobiphenyl, 2.6 g of a whitecrystal was obtained (yield: 35%), which was identified by FD-MSanalysis as the following compound (HA13).

Synthesis Example A14 Production of Compound (HA14)

In the same manner as in Synthesis Example A1 except for using 4.0 g ofthe intermediate (1-8) in place of 4-bromobiphenyl, 2.5 g of a whitecrystal was obtained (yield: 30%), which was identified by FD-MSanalysis as the following compound (HA14).

Synthesis Example A15 Production of Compound (HA15)

In the same manner as in Synthesis Example A1 except for using 4.0 g ofthe intermediate (1-9) in place of 4-bromobiphenyl, 2.4 g of a whitecrystal was obtained (yield: 28%), which was identified by FD-MSanalysis as the following compound (HA15).

Synthesis Example A16 Production of compound (HA16))

Under an argon atmosphere, into a mixture of 2.3 g (10.0 mmol) of4-bromobiphenyl, 6.0 g (10.0 mmol) of the intermediate (A2-3), 0.14 g(0.15 mmol) of Pd₂(dba)₃, 0.087 g (0.3 mmol) of P(^(t)Bu)₃HBF₄, and 1.9g (20.0 mmol) of sodium t-butoxide, 50 ml of dehydrated xylene wasadded, and the resultant mixture was refluxed for 8 h under heating.

After the reaction, the reaction mixture was cooled to 50° C. andfiltered through celite/silica gel. The filtrate was concentrated andthe residual concentrate was purified by column chromatography to obtaina white solid. The crude product was recrystallized from toluene toobtain 2.3 g of a white crystal (yield: 30%), which was identified byFD-MS analysis as the following compound (HA16).

Synthesis Example A17 Production of Compound (HA17)

In the same manner as in Synthesis Example A16 except for using 2.3 g of2-bromobiphenyl in place of 4-bromobiphenyl, 2.0 g of a white crystalwas obtained (yield: 27%), which was identified by FD-MS analysis as thefollowing compound (HA17).

Synthesis Example A18 Production of Compound (HA18)

In the same manner as in Synthesis Example A16 except for using 3.1 g of4-bromoterphenyl in place of 4-bromobiphenyl, 2.9 g of a white crystalwas obtained (yield: 35%), which was identified by FD-MS analysis as thefollowing compound (HA18).

Example 1-1 Production of Organic EL Device

A glass substrate of 25 mm×75 mm×1.1 mm having an ITO transparentelectrode (product of Geomatec Company) was cleaned by ultrasoniccleaning in isopropyl alcohol for 5 min and then UV (ultraviolet) ozonecleaning for 30 min.

The cleaned glass substrate having a transparent electrode line wasmounted to a substrate holder of a vacuum vapor deposition apparatus.First, the following electron-accepting compound (A) was vapor-depositedso as to cover the transparent electrode to form a film A with athickness of 10 nm.

On the film A, the following aromatic amine derivative (X1) as a firsthole transporting material was vapor-deposited to form a first holetransporting layer with a thickness of 80 nm. Successively after formingthe first hole transporting layer, the following compound (HA1) as asecond hole transporting material was vapor-deposited to form a secondhole transporting layer with a thickness of 10 nm.

On the hole transporting layer, the host compound (BH) and the dopantcompound (BD) were vapor co-deposited into a thickness of 25 nm to forma light emitting layer. The concentration of the dopant compound (BD)was 4% by mass.

Thereafter, on the light emitting layer, the following compound (ET1),the following compound (ET2), and LiF were vapor-deposited into athickness of 25 nm, 10 nm, and 1 nm, respectively, to form an electrontransporting/injecting layer. Further, metallic Al was deposited into athickness of 80 nm to form a cathode, thereby producing an organic ELdevice.

Examples 1-2 to 1-18 Production of Organic EL Device

Each organic EL device of Examples 1-2 to 1-18 was produce in the samemanner as in Example 1-1 except for using each of the compoundsdescribed in Table 1 as the second hole transporting material.

Comparative Examples 1-1 and 1-2 Production of Organic EL Device

Each organic EL device of Comparative Examples 1-1 and 1-2 was producedin the same manner as in Example 1-1 except for using each of thefollowing comparative compounds described in Table 1 as the second holetransporting material.

Evaluation of Emission Efficiency of Organic EL Device

Each organic EL device thus produced was allowed to emit light bydriving at a constant current to measure the luminance (L) and thecurrent density. From the measured results, the current efficiency (L/J)and the driving voltage (V) at a current density of 10 mA/cm² weredetermined. In addition, the lifetime at a current density of 50 mA/cm²was determined. The 80% lifetime is the time taken until the luminanceis reduced to 80% of the initial luminance when driving at a constantcurrent. The results are shown in Table 1.

TABLE 1 Measured results Emission Driving efficiency voltage First holeSecond hole (cd/A) (V) 80% transporting transporting @10 mA/ @10 mA/lifetime material material cm² cm² (h) Examples 1-1 X1 HA1 9.4 3.9 3001-2 X1 HA2 9.5 3.9 300 1-3 X1 HA3 9.2 3.8 300 1-4 X1 HA4 9.6 4.1 300 1-5X1 HA5 9.8 4.1 280 1-6 X1 HA6 9.6 4.1 280 1-7 X1 HA7 9.8 4.1 260 1-8 X1HA8 9.8 4.0 300 1-9 X1 HA9 9.4 3.7 300 1-10 X1 HA10 9.5 3.7 300 1-11 X1HA11 9.2 3.6 270 1-12 X1 HA12 9.4 3.7 330 1-13 X1 HA13 9.3 3.5 270 1-14X1 HA14 10.0 4.1 310 1-15 X1 HA15 10.0 4.0 300 1-16 X1 HA16 9.4 3.8 3201-17 X1 HA17 9.6 3.8 320 1-18 X1 HA18 9.4 3.6 330 Com- parative Examples1-1 X1 Comparative 9.5 3.8 200 compound 1 1-2 X1 Comparative 9.8 3.9 220compound 2

As seen from Table 1, it can be found that an organic EL device capableof driving at a low voltage and having high emission efficiency and longlifetime can be obtained by using the compounds (HA1) to (HA18) withinthe compound (A1) in an aspect of the invention.

Example 2-1 Production of Organic EL Device

A glass substrate of 25 mm×75 mm×1.1 mm having an ITO transparentelectrode (product of Geomatec Company) was cleaned by ultrasoniccleaning in isopropyl alcohol for 5 min and then UV (ultraviolet) ozonecleaning for 30 min.

The cleaned glass substrate having a transparent electrode line wasmounted to a substrate holder of a vacuum vapor deposition apparatus.First, the following electron-accepting compound (A) was vapor-depositedso as to cover the transparent electrode to form a film A with athickness of 10 nm.

On the film A, the above compound (HA1) as a first hole transportingmaterial was vapor-deposited to form a first hole transporting layerwith a thickness of 80 nm. Successively after forming the first holetransporting layer, the following aromatic amine derivative (Y1) as asecond hole transporting material was vapor-deposited to form a secondhole transporting layer with a thickness of 10 nm.

On the hole transporting layer, the above host compound (BH) and theabove dopant compound (BD) were vapor co-deposited into a thickness of25 nm to form a light emitting layer. The concentration of the dopantcompound (BD) was 4% by mass.

Thereafter, on the light emitting layer, the above compound (ET1), theabove compound (ET2), and LiF were vapor-deposited into a thickness of25 nm, 10 nm, and 1 nm, respectively, to form an electrontransporting/injecting layer. Further, metallic Al was deposited into athickness of 80 nm to form a cathode, thereby producing an organic ELdevice.

Examples 2-2 to 2-18 Production of Organic EL Device

Each organic EL device of Examples 2-2 to 2-18 was produced in the samemanner as in Example 2-1 except for using each compound described inTable 2 as the first hole transporting material.

Examples 2-19 and 2-20 Production of Organic EL Device

Each organic EL device of Examples 2-19 and 2-20 was produced in thesame manner as in Examples 2-1 and 2-2 except for using the followingcompound (EA2) in place of the electron-accepting compound (A).

Comparative Examples 2-1 and 2-2 Production of Organic EL Device

Each organic EL device of Comparative Examples 2-1 and 2-2 was producedin the same manner as in Example 2-1 except for using each comparativecompound described in Table 2 as the first hole transporting material.

Comparative Example 2-3 and 2-4 Production of Organic EL Device

Each organic EL device of Comparative Example 2-3 and 2-4 was producedin the same manner as in Examples 2-19 and 2-20 except for using eachcomparative compound described in Table 2 as the first hole transportingmaterial.

Evaluation of Emission Efficiency of Organic EL Device

Each organic EL device thus produced was allowed to emit light bydriving at a constant current to measure the luminance (L) and thecurrent density. From the measured results, the current efficiency (L/J)and the driving voltage (V) at a current density of 10 mA/cm² weredetermined. In addition, the lifetime at a current density of 50 mA/cm²was determined. The 80% lifetime is the time taken until the luminanceis reduced to 80% of the initial luminance when driving at a constantcurrent. The results are shown in Table 2.

TABLE 2 Measured results Emission Driving efficiency voltage First holeSecond hole (cd/A) (V) 80% transporting transporting @10 mA/ @10 mA/lifetime material material cm² cm² (h) Examples 2-1 HA1 Y1 9.7 3.6 3202-2 HA2 Y1 9.7 3.6 320 2-3 HA3 Y1 9.5 3.6 330 2-4 HA4 Y1 9.5 3.7 340 2-5HA5 Y1 10.0 3.7 340 2-6 HA6 Y1 9.5 3.7 330 2-7 HA7 Y1 9.9 3.7 330 2-8HA8 Y1 10.0 3.6 320 2-9 HA9 Y1 9.7 3.6 340 2-10 HA10 Y1 9.7 3.6 340 2-11HA11 Y1 9.6 3.6 330 2-12 HA12 Y1 9.7 3.6 350 2-13 HA13 Y1 9.9 3.5 2802-14 HA14 Y1 10.2 3.8 320 2-15 HA15 Y1 10.2 3.8 310 2-16 HA16 Y1 9.7 3.5330 2-17 HA17 Y1 9.8 3.4 320 2-18 HA18 Y1 9.6 3.5 350 2-19 HA1 Y1 9.63.4 340 2-20 HA2 Y1 9.7 3.4 340 Com- parative Examples 2-1 ComparativeY1 9.5 3.9 250 compound 1 2-2 Comparative Y1 9.5 4.0 220 compound 2 2-3Comparative Y1 9.5 3.7 250 compound 1 2-4 Comparative Y1 9.5 3.8 210compound 2

As seen from Table 2, it can be found that an organic EL device capableof driving at a low voltage and having high emission efficiency and longlifetime can be obtained by using the compounds (HA1) to (HA18) withinthe compound (A1) of the invention.

Synthesis of Compound (B1)

The intermediates 1-1 to 1-6, 1-8, and 1-9 are the same as describedabove with respect to the synthesis of the compound (A1).

Intermediate Synthesis B1-7 (Synthesis of Intermediate (B1-7))

Under an argon atmosphere, into a mixture of 39.7 g (100.0 mmol) of4-bromo-9,9′-diphenylfluorene, 16.4 g (105.0 mmol) of4-chlorophenylboronic acid, and 2.31 g (2.00 mmol) of Pd[PPh₃]₄, 150 mlof toluene, 150 ml of dimethoxyethane, and 150 ml (300.0 mmol) of a 2 Maqueous solution of Na₂CO₃ were added, and the resultant mixture wasrefluxed for 10 h under heating and stirring.

After the reaction, the reaction mixture was cooled to room temperatureand extracted with dichloromethane in a separating funnel. The organiclayer was dried over MgSO₄, filtered, and concentrated. The residualconcentrate was purified by column chromatography to obtain 32.2 g of awhite solid (yield: 75%), which was identified by FD-MS analysis as thefollowing intermediate (B1-7).

Intermediate Synthesis B2-1 (Synthesis of Intermediate (B2-1))

Under an argon atmosphere, into a mixture of 19.9 g (50.0 mmol) of4-bromo-9,9′-diphenylfluorene, 10.5 g (50.0 mmol) of2-amino-9,9′-dimethylfluorene, and 9.6 g (100.0 mmol) of sodiumt-butoxide, 250 ml of dehydrated toluene was added, and the resultantmixture was stirred. After further adding 225 mg (1.0 mmol) of palladiumacetate and 202 mg (1.0 mmol) of tri-t-butylphosphine, the mixture wasallowed to react at 80° C. for 8 h.

After cooling, the reaction mixture was filtered through celite/silicagel, and the filtrate was concentrated under reduced pressure. Theobtained residue was recrystallized from toluene, and the crystalcollected by filtration was dried to obtain 19.7 g of a white solid(yield: 75%), which was identified by FD-MS analysis as the followingintermediate (B2-1).

Intermediate Synthesis B2-2 (Synthesis of Intermediate (B2-2))

In the same manner as in Intermediate Synthesis B2-1 except for using21.4 g of the intermediate (B1-7) in place of4-bromo-9,9′-diphenylfluorene, 21.1 g of a white solid was obtained(yield: 70%), which was identified by FD-MS analysis as the followingintermediate (B2-2).

Intermediate Synthesis B2-3 (Synthesis of Intermediate (B2-3))

Under an argon atmosphere, a mixture of 17.2 g (100.0 mmol) of4-bromoaniline, 25.0 g (105.0 mmol) of 9,9′-dimethylfluorene-2-boronicacid, and 2.31 g (2.00 mmol) of Pd[PPh₃]₄, 150 ml of toluene, 150 ml ofdimethoxyethane, and 150 ml (300.0 mmol) of a 2 M aqueous solution ofNa₂CO₃ were added, and the resultant mixture was refluxed for 10 h underheating and stirring.

After the reaction, the reaction mixture was cooled to room temperatureand extracted with dichloromethane in a separating funnel. The organiclayer was dried over MgSO₄, filtered, and concentrated. The residualconcentrate was purified by column chromatography to obtain 11.4 g of awhite solid (yield: 40%), which was identified by FD-MS analysis as thefollowing intermediate (B2-3).

Intermediate Synthesis B2-4 (Synthesis of Intermediate (B2-4))

Under an argon atmosphere, into a mixture of 19.9 g (50.0 mmol) of4-bromo-9,9′-diphenylfluorene, 14.3 g (50.0 mmol) of the intermediate(B2-3), and 9.6 g (100.0 mmol) of sodium t-butoxide, 250 ml ofdehydrated toluene was added, and the resultant mixture was stirred.After further adding 225 mg (1.0 mmol) of palladium acetate and 202 mg(1.0 mmol) of tri-t-butylphosphine, the mixture was allowed to react at80° C. for 8 h.

After cooling, the reaction mixture was filtered through celite/silicagel, and the filtrate was concentrated under reduced pressure. Theobtained residue was recrystallized from toluene, and the precipitatedcrystal was collected by filtration and dried to obtain 19.0 g of awhite solid (yield: 63%), which was identified by FD-MS analysis as thefollowing intermediate (B2-4).

Synthesis Example B1 Production of Compound (HB1)

Under an argon atmosphere, into a mixture of 2.3 g (10.0 mmol) of2-bromobiphenyl, 5.3 g (10.0 mmol) of the intermediate (B2-1), 0.14 g(0.15 mmol) of Pd₂(dba)₃, 0.087 g (0.3 mmol) of P(^(t)Bu)₃HBF₄, and 1.9g (20.0 mmol) of sodium t-butoxide, 50 ml of dehydrated xylene wasadded, and the resultant mixture was refluxed for 8 h under heating.

After the reaction, the reaction mixture was cooled to 50° C. andfiltered through celite/silica gel. The filtrate was concentrated andthe residual concentrate was purified by column chromatography to obtaina white solid. The crude product was recrystallized from toluene toobtain 2.0 g of a white crystal (yield: 30%), which was identified byFD-MS analysis as the following compound (HB1).

Synthesis Example B2 Production of compound (HB2)

In the same manner as in Synthesis Example B1 except for using 2.3 g of4-bromobiphenyl in place of 2-bromobiphenyl, 2.6 g of a white crystalwas obtained (yield: 38%), which was identified by FD-MS analysis as thefollowing compound (HB2).

Synthesis Example B3 Production of Compound (HB3)

In the same manner as in Synthesis Example B1 except for using 2.7 g of2-bromo-9,9′-dimethylfluorene in place of 2-bromobiphenyl, 2.5 g of awhite crystal was obtained (yield: 35%), which was identified by FD-MSanalysis as the following compound (HB3).

Synthesis Example B4 Production of Compound (HB4)

In the same manner as in Synthesis Example B1 except for using 4.0 g of2-bromo-9,9′-diphenylfluorene in place of 2-bromobiphenyl, 2.5 g of awhite crystal was obtained (yield: 30%), which was identified by FD-MSanalysis as the following compound (HB4).

Synthesis Example B5 Production of Compound (HB5)

In the same manner as in Synthesis Example B1 except for using 3.2 g ofthe intermediate (1-1) in place of 2-bromobiphenyl, 2.2 g of a whitecrystal was obtained (yield: 28%), which was identified by FD-MSanalysis as the following compound (HB5).

Synthesis Example B6 Production of Compound (HB6)

In the same manner as in Synthesis Example B1 except for using 3.2 g ofthe intermediate (1-2) in place of 2-bromobiphenyl, 2.7 g of a whitecrystal was obtained (yield: 35%), which was identified by FD-MSanalysis as the following compound (HB6).

Synthesis Example B7 Production of Compound (HB7)

In the same manner as in Synthesis Example B1 except for using 3.4 g ofthe intermediate (1-3) in place of 2-bromobiphenyl, 2.6 g of a whitecrystal was obtained (yield: 33%), which was identified by FD-MSanalysis as the following compound (HB7).

Synthesis Example B8 Production of Compound (HB8)

In the same manner as in Synthesis Example B1 except for using 3.4 g ofthe intermediate (1-4) in place of 2-bromobiphenyl, 2.2 g of a whitecrystal was obtained (yield: 28%), which was identified by FD-MSanalysis as the following compound (HB8).

Synthesis Example B9 Production of Compound (HB9)

In the same manner as in Synthesis Example B1 except for using 4.0 g ofthe intermediate (1-6) in place of 2-bromobiphenyl, 2.5 g of a whitecrystal was obtained (yield: 30%), which was identified by FD-MSanalysis as the following compound (HB9).

Synthesis Example B10 Production of Compound (HB10)

Under an argon atmosphere, into a mixture of 2.3 g (10.0 mmol) of2-bromobiphenyl, 6.0 g (10.0 mmol) of the intermediate (B2-2), 0.14 g(0.15 mmol) of Pd₂(dba)₃, 0.087 g (0.3 mmol) of P(^(t)Bu)₃HBF₄, and 1.9g (20.0 mmol) of sodium t-butoxide, 50 ml of dehydrated xylene wasadded, and the resultant mixture was refluxed for 8 h under heating.

After the reaction, the reaction mixture was cooled to 50° C. andfiltered through celite/silica gel. The filtrate was concentrated andthe residual concentrate was purified by column chromatography to obtaina white solid. The crude product was recrystallized from toluene toobtain 2.0 g of a white crystal (yield: 27%), which was identified byFD-MS analysis as the following compound (HB10).

Synthesis Example B11 Production of Compound (HB11)

In the same manner as in Synthesis Example B10 except for using 2.3 g of4-bromobiphenyl in place of 2-bromobiphenyl, 2.5 g of a white crystalwas obtained (yield: 33%), which was identified by FD-MS analysis as thefollowing compound (HB11).

Synthesis Example B12 Production of Compound (HB12)

In the same manner as in Synthesis Example B10 except for using 2.7 g of2-bromo-9,9′-dimethylfluorene in place of 2-bromobiphenyl, 2.4 g of awhite crystal was obtained (yield: 30%), which was identified by FD-MSanalysis as the following compound (HB12).

Synthesis Example B13 Production of Compound (HB13)

In the same manner as in Synthesis Example B10 except for using 4.0 g of2-bromo-9,9′-diphenylfluorene in place of 2-bromobiphenyl, 2.6 g of awhite crystal was obtained (yield: 28%), which was identified by FD-MSanalysis as the following compound (HB13).

Synthesis Example B14 Production of Compound (HB14)

In the same manner as in Synthesis Example B1 except for using 3.1 g of4-bromoterphenyl in place of 2-bromobiphenyl, 2.6 g of a white crystalwas obtained (yield: 35%), which was identified by FD-MS analysis as thefollowing compound (HB14).

Synthesis Example B15 Production of Compound (HB15)

In the same manner as in Synthesis Example B1 except for using 3.1 g of2-bromotriphenylene in place of 2-bromobiphenyl, 2.7 g of a whitecrystal was obtained (yield: 36%), which was identified by FD-MSanalysis as the following compound (HB15).

Synthesis Example B16 Production of Compound (HB16)

In the same manner as in Synthesis Example B1 except for using 4.0 g ofthe intermediate (1-8) in place of 2-bromobiphenyl, 2.0 g of a whitecrystal was obtained (yield: 24%), which was identified by FD-MSanalysis as the following compound (HB16).

Synthesis Example B17 Production of Compound (HB17)

In the same manner as in Synthesis Example B1 except for using 4.0 g ofthe intermediate (1-9) in place of 2-bromobiphenyl, 1.7 g of a whitecrystal was obtained (yield: 20%), which was identified by FD-MSanalysis as the following compound (HB17).

Synthesis Example B18 Production of Compound (HB18)

Under an argon atmosphere, into a mixture of 2.3 g (10.0 mmol) of4-bromobiphenyl, 6.0 g (10.0 mmol) of the intermediate (B2-4), 0.14 g(0.15 mmol) of Pd₂(dba)₃, 0.087 g (0.3 mmol) of P(^(t)Bu)₃HBF₄, and 1.9g (20.0 mmol) of sodium t-butoxide, 50 ml of dehydrated xylene wasadded, and the resultant mixture was refluxed for 8 h under heating.

After the reaction, the reaction mixture was cooled to 50° C. andfiltered through celite/silica gel. The filtrate was concentrated andthe residual concentrate was purified by column chromatography to obtaina white solid. The crude product was recrystallized from toluene toobtain 2.6 g of a white crystal (yield: 34%), which was identified byFD-MS analysis as the following compound (HB18).

Synthesis Example B19 Production of Compound (HB19)

In the same manner as in Synthesis Example B18 except for using 2.3 g of2-bromobiphenyl in place of 4-bromobiphenyl, 2.1 g of a white crystalwas obtained (yield: 28%), which was identified by FD-MS analysis as thefollowing compound (HB19).

Synthesis Example B20 Production of Compound (HB20)

In the same manner as in Synthesis Example B18 except for using 3.1 g of4-bromoterphenyl in place of 4-bromobiphenyl, 2.9 g of a white crystalwas obtained (yield: 35%), which was identified by FD-MS analysis as thefollowing compound (HB20).

Examples 3-1 to 3-20 Production of Organic EL Device

Each organic EL device of Examples 3-1 to 3-20 was produced in the samemanner as in Example 1-1 except for using each compound described inTable 3 as the second hole transporting material.

Comparative Examples 3-1 to 3-4

Each organic EL device of Comparative Examples 3-1 to 3-4 was producedin the same manner as in Example 3-1 except for using each of thefollowing comparative compounds 3 to 6 as the second hole transportingmaterial.

Evaluation of Emission Efficiency of Organic EL Device

Each organic EL device thus produced was allowed to emit light bydriving at a constant current to measure the luminance (L) and thecurrent density. From the measured results, the emission efficiency(cd/A) and the driving voltage (V) at a current density of 10 mA/cm²were determined. In addition, the 80% lifetime at a current density of50 mA/cm² was determined. The 80% lifetime is the time taken until theluminance is reduced to 80% of the initial luminance when driving at aconstant current. The results are shown in Table 3.

TABLE 3 Measured results Emission Driving efficiency voltage First holeSecond hole (cd/A) (V) 80% transporting transporting @10 mA/ @10 mA/lifetime material material cm² cm² (h) Examples 3-1 X1 HB1 9.5 4.2 2803-2 X1 HB2 9.4 4.2 280 3-3 X1 HB3 9.2 4.0 290 3-4 X1 HB4 9.3 4.1 290 3-5X1 HB5 9.6 4.3 290 3-6 X1 HB6 9.8 4.3 270 3-7 X1 HB7 9.6 4.3 280 3-8 X1HB8 9.8 4.3 260 3-9 X1 HB9 9.8 4.2 280 3-10 X1 HB10 9.5 4.0 280 3-11 X1HB11 9.4 4.0 280 3-12 X1 HB12 9.2 3.8 270 3-13 X1 HB13 9.3 3.9 270 3-14X1 HB14 9.4 4.0 320 3-15 X1 HB15 9.4 4.0 280 3-16 X1 HB16 10.0 4.3 2903-17 X1 HB17 10.0 4.3 290 3-18 X1 HB18 9.4 4.2 320 3-19 X1 HB19 9.5 4.3300 3-20 X1 HB20 9.4 4.2 330 Com- parative Examples 3-1 X1 Comparative9.8 4.8 200 compound 3 3-2 X1 Comparative 9.8 4.9 220 compound 4 3-3 X1Comparative 9.8 4.3 220 compound 5 3-4 X1 Comparative 9.8 5.2 150compound 6

As seen from Table 3, it can be seen that an organic EL device which iscapable of driving at a low voltage while maintaining the emissionefficiency at a high level and has a long lifetime is obtained by usingthe compounds (HB1) to (HB20) within the compound (B1) in an aspect ofthe invention. Particularly, the effect for improving the lifetime islarge.

The compounds (HB1) to (HB20) within the compound (B1) in an aspect ofthe invention are structurally characterized by:

-   (1) the 9,9-diarylfluorene-4-yl group;-   (2) the 9,9-dialkylfluorene-2-yl group; and-   (3) the fused aromatic hydrocarbon ring having a high electron    density, such as a naphthalene ring and a phenanthrene ring, or the    aromatic heterocyclic ring having a high electron density, such as a    dibenzofuran ring and a dibenzothiophene ring, each being not    directly bonded to the nitrogen atom.

By combining the characteristics (1) to (3), the durability to charge ofthe compounds (HB1) to (HB20) is provably enhanced to prolong thelifetime of the organic EL device.

One of the factors which affect the durability to charge would be thedistribution of HOMO molecular orbital throughout the molecule. Itappears that a compound in which HOMO is widely distributed throughoutits molecule has a high durability to charge, and in contrast, acompound in which the distribution is narrow and the electron density islocally high has a low durability to charge.

HOMO scarcely distributes on the 9,9-diphenylfluorene-4-yl group becauseof its large distortional conformation. Therefore, the degree of HOMOdistribution may depend on the other two groups on the nitrogen atom. Ifthe other two groups are a fused aromatic hydrocarbon ring having a highelectron density and an aromatic heterocyclic group having a highelectron density which are both directly bonded to the nitrogen atom, itis probable that HOMO distribution is highly localized in the vicinityof the central nitrogen atom, thereby likely to reduce the durability tocharge.

In the comparative compound 5, the fused aromatic hydrocarbon ringhaving a high electron density, i.e. the phenanthrene ring, is directlybonded to the nitrogen atom. Therefore, its durability to charge isprobably reduced for the reasons mentioned above.

On the other hand, since the compounds (HB1) to (HB20) combine the abovecharacteristics (1) to (3), particularly meet the characteristic (3),HOMO widely distributes throughout their molecules to form the structurestable to charge, this probably resulting in the effect of prolongingthe lifetime of the organic EL device.

Examples 4-1 to 4-20 Production of Organic EL Device

Each organic EL device of Examples 4-1 to 4-20 was produced in the samemanner as in Example 2-1 except for using each compound shown in Table 4as the first hole transporting material.

Examples 4-21 and 4-22 Production of Organic EL Device

Each organic EL device of Examples 4-21 and 4-22 was produced in thesame manner as in Examples 4-1 and 4-2 except for using the followingcompound (EA2) in place of the electron-accepting compound (A).

Comparative Examples 4-1 to 4-4

Each organic EL device of Comparative Examples 4-1 to 4-4 was producedin the same manner as in Examples 4-1 to 4-13 except for using each ofthe above comparative compounds 3 to 6 shown in Table 4 as the firsthole transporting material.

Comparative Examples 4-5 to 4-8

Each organic EL device of Comparative Examples 4-5 to 4-8 was producedin the same manner as in Examples 4-2 land 4-22 except for using each ofthe above comparative compounds 3 to 6 shown in Table 4 as the firsthole transporting material.

Evaluation of Emission Efficiency of Organic EL Device

Each organic EL device thus produced was measured for the emissionefficiency (cd/A) and the driving voltage (V) at a current density of 10mA/cm² and the 80% lifetime at a current density of 50 mA/cm² in thesame manner as in Example 3-1. The results are shown in Table 4.

TABLE 4 Measured results Emission Driving efficiency voltage First holeSecond hole (cd/A) (V) 80% transporting transporting @10 mA/ @10 mA/lifetime material material cm² cm² (h) Examples 4-1 HB1 Y1 9.5 4.1 3004-2 HB2 Y1 9.5 4.2 300 4-3 HB3 Y1 9.3 4.0 310 4-4 HB4 Y1 9.3 4.1 310 4-5HB5 Y1 9.3 4.2 300 4-6 HB6 Y1 9.6 4.2 300 4-7 HB7 Y1 9.3 4.2 290 4-8 HB8Y1 9.6 4.2 290 4-9 HB9 Y1 9.5 4.2 290 4-10 HB10 Y1 9.5 4.1 320 4-11 HB11Y1 9.5 4.2 320 4-12 HB12 Y1 9.4 4.0 310 4-13 HB13 Y1 9.4 4.1 320 4-14HB14 Y1 9.5 4.0 350 4-15 HB15 Y1 9.4 4.0 300 4-16 HB16 Y1 10.1 4.4 3004-17 HB17 Y1 10.0 4.4 300 4-18 HB18 Y1 9.5 4.2 320 4-19 HB19 Y1 9.5 4.1320 4-20 HB20 Y1 9.4 4.2 350 4-21 HB1 Y1 9.5 3.8 320 4-22 HB2 Y1 9.6 3.8330 Com- parative Examples 4-1 Comparative Y1 9.5 4.8 250 compound 3 4-2Comparative Y1 9.5 5.4 220 compound 4 4-3 Comparative Y1 9.3 4.8 200compound 5 4-4 Comparative Y1 8.5 5.7 130 compound 6 4-5 Comparative Y19.4 4.6 260 compound 3 4-6 Comparative Y1 9.5 5.2 250 compound 4 4-7Comparative Y1 9.3 4.6 220 compound 5 4-8 Comparative Y1 8.4 5.7 140compound 6

As seen from Table 4, it can be seen that an organic EL device which iscapable of driving at a low voltage while maintaining the emissionefficiency at a high level and has long lifetime is obtained by usingthe compounds (HB1) to (HB20) within the compound (B1) in an aspect ofthe invention.

REFERENCE SIGNS LIST

-   1: Organic EL device-   2: Substrate-   3: Anode-   4: Cathode-   5: Light emitting layer-   6: Anode-side organic thin film layer-   7: Cathode-side organic thin film layer-   10: Emission unit

1. A compound represented by formula (A1) or (B1):

wherein R¹ to R⁶ each independently represent a substituted orunsubstituted alkyl group having 1 to 20 carbon atoms, a substituted orunsubstituted aryl group having 6 to 50 ring carbon atoms, a substitutedor unsubstituted heteroaryl group having 5 to 50 ring atoms, a halogenatom, a substituted or unsubstituted fluoroalkyl group having 1 to 20carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20carbon atoms, a substituted or unsubstituted fluoroalkoxy group having 1to 20 carbon atoms, a substituted or unsubstituted aryloxy group having6 to 50 ring carbon atoms, or a cyano group; when R¹ to R⁶ are eachplurality in number, groups R¹ to groups R⁶ may be are the same ordifferent; R⁵ and R⁶ may be are optionally bonded to each other to forma ring structure; R⁷ and R⁸ each independently represent a hydrogenatom, a substituted or unsubstituted alkyl group having 1 to 20 carbonatoms, a substituted or unsubstituted fluoroalkyl group having 1 to 20carbon atoms, or a cyano group, and R⁷ and R⁸ may be are optionallybonded to each other to form a saturated aliphatic ring; k3 and k4 eachindependently represent an integer of 0 to 5, m2 and m6 eachindependently represent an integer of 0 to 4, and n1 and n5 eachindependently represent an integer of 0 to 3; L⁰ to L² eachindependently represent a single bond, a substituted or unsubstitutedarylene group having 6 to 50 ring carbon atoms, or a substituted orunsubstituted heteroarylene group having 5 to 50 ring atoms; Arrepresents a substituted or unsubstituted aryl group having 6 to 50 ringcarbon atoms or a substituted or unsubstituted heteroaryl group having 5to 40 ring atoms.
 2. The compound according to claim 1, wherein thecompound is represented by formula (A1-1):

wherein R¹ to R⁸, n1, m2, k3, k4, n5, m6, L¹, L², and Ar are defined inclaim
 1. 3. The compound according to claim 1, wherein the compound isrepresented by formula (A1-2):

wherein R¹ to R⁸, n1, m2, k3, k4, n5, m6, L⁰ to L², and Ar arc definedin claim
 1. 4. The compound according to claim 1, wherein the compoundis represented by formula (A1-2-1):

wherein R¹ to R⁸, n1, m2, k3, k4, n5, m6, L², and Ar are defined inclaim
 1. 5. The compound according to claim 1, wherein the compound isrepresented by formula (A1-3):

wherein R¹, R², R⁵, R⁶, n1, m2, n5, m6, L⁰ to L², and Ar are defined inclaim
 1. 6. The compound according to claim 1, wherein the compound isrepresented by formula (A1-4):

wherein L⁰ to L², and Ar are defined in claim
 1. 7. The compoundaccording to claim 1, wherein Ar is a group represented by any offormulae (a) to (k):

wherein R, R^(a), and R^(b) are each independently R¹ defined in claim1, when more than one R occurs, groups R are the same or different, andtwo groups R are optionally bonded to each other to form a ringstructure; R^(c) represents a hydrogen atom, a substituted orunsubstituted alkyl group having 1 to 20 carbon atoms, a substituted orunsubstituted aryl group having 6 to 50 ring carbon atoms, or asubstituted or unsubstituted heteroaryl group having 5 to 50 ring atoms;two groups selected from groups R, R^(a), and R^(b) in formula (f) areoptionally bonded to each other to form a ring structure; each kindependently represents an integer of 0 to 5, each m independentlyrepresents an integer of 0 to 4, each n independently represents aninteger of 0 to 3; and represents a bonding site to L² or the nitrogenatom.
 8. The compound according to claim 1, wherein the compound isrepresented by the formula (B1), and Ar in the formula (B1) is a grouprepresented by any of formulae (a) to (j):

wherein each R is independently R¹ defined in claim 1, when more thanone R occurs, groups R are the same or different, and two groups R areoptionally bonded to each other to form a ring structure; R^(a) andR^(b) in formula (f) each independently represent a hydrogen atom, asubstituted or unsubstituted alkyl group having 1 to 20 carbon atoms, asubstituted or unsubstituted aryl group having 6 to 50 ring carbonatoms, a substituted or unsubstituted heteroaryl group having 5 to 50ring atoms, a halogen atom, a substituted or unsubstituted fluoroalkylgroup having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxygroup having 1 to 20 carbon atoms, a substituted or unsubstitutedfluoroalkoxy group having 1 to 20 carbon atoms, a substituted orunsubstituted aryloxy group having 6 to 50 ring carbon atoms, or a cyanogroup, and two groups selected from groups R, R^(a), and R^(b) informula (f) are optionally bonded to each other to form a ringstructure; each k independently represents an integer of 0 to 5, each mindependently represents an integer of 0 to 4, and each n independentlyrepresents an integer of 0 to 3; and * represents a bonding site to L²or the nitrogen atom in the formula (B1).
 9. The compound according toclaim 8, wherein L¹ is a substituted or unsubstituted arylene grouphaving 6 to 50 ring carbon atoms or a substituted or unsubstitutedheteroarylene group having 5 to 50 ring atoms.
 10. The compoundaccording to claim 8, wherein L² is a substituted or unsubstitutedarylene group having 6 to 50 ring carbon atoms or a substituted orunsubstituted heteroarylene group having 5 to 50 ring atoms.
 11. Thecompound according to claim 8, wherein the compound is represented byformula (B1-1):

wherein R¹ to R⁸, n1, m2, k3, k4, n5, m6, L¹, L², and Ar are [[as]]defined in claim
 8. 12. The compound according to claim 11, wherein L¹in formula (B1-1) is a substituted or unsubstituted arylene group having6 to 50 ring carbon atoms or a substituted or unsubstitutedheteroarylene group having 5 to 50 ring atoms.
 13. The compoundaccording to claim 8, wherein the compound is represented by formula(B1-2):

wherein R¹ to R⁸, n1, m2, k3, k4, n5, m6, L², and Ar are defined inclaim
 8. 14. The compound according to claim 8, wherein the compound isrepresented by formula (B1-3):

wherein R¹, R², R⁵, R⁶, n1, m2, n5, m6, L⁰ to L², and Ar are defined inclaim
 8. 15. The compound according to claim 8, wherein the compound isrepresented by formula (B1-4):

wherein L⁰ to L², and Ar are defined in claim
 8. 16. The compoundaccording to claim 1, wherein L⁰ is a substituted or unsubstitutedarylene group having 6 to 50 ring carbon atoms.
 17. The compoundaccording to claim 7, wherein Ar is a group represented by any offormulae (b-1), (b-2), (c-1), (c-2), and (d-1):

wherein R, k, m, n, and * are defined in claim
 7. 18. The compoundaccording to claim 1, wherein L⁰ to L² each independently represent asingle bond or a group represented by any of formulae (i) and (ii):

wherein each R is R¹ in claim 1, when more than one R occurs, groups Rare the same or different, and two groups R are optionally bonded toeach other to form a ring structure; each m independently represents aninteger of 0 to 4; and * and ** each represent a bonding site.
 19. Thecompound according to claim 18, wherein L⁰ to L² each independentlyrepresent a single bond or a group represented by any of formulae (i-a)and (ii-a):

wherein R, m, *, and ** are defined in claim
 18. 20. The compoundaccording to claim 8, wherein Ar is a group represented by any of thefollowing formulae:

wherein * represents a bonding site to L² or the nitrogen atom.
 21. Thecompound according to claim 1, wherein -L²-Ar is a group represented byany of the following groups:

wherein * represents a bonding site to the nitrogen atom, and R^(c)represents a hydrogen atom, a substituted or unsubstituted alkyl grouphaving 1 to 20 carbon atoms, a substituted or unsubstituted aryl grouphaving 6 to 50 ring carbon atoms, or a substituted or unsubstitutedheteroaryl group having 5 to 50 ring atoms.
 22. The compound accordingto claim 1, wherein the compound is one selected from the groupconsisting of the following compounds:


23. The compound according to claim 1, wherein the compound is oneselected from the group consisting of the following compounds:


24. A material for an organic electroluminescence device, the materialcomprising the compound according to claim
 1. 25. An organicelectroluminescence device, comprising a cathode, an anode, and at leastone organic thin film layer disposed between the cathode and the anode,wherein the at least one organic thin film layer comprises a lightemitting layer and at least one layer of the at least one organic thinfilm layer comprises the compound according to claim
 1. 26. The organicelectroluminescence device according to claim 25, wherein the at leastone organic thin film layer comprises at least one selected from thegroup consisting of a hole injecting layer comprising the compound and ahole transporting layer comprising the compound.
 27. The organicelectroluminescence device according to claim 25, wherein the at leastone organic thin film layer comprises a first hole transporting layerand a second hole transporting layer sequentially from the anode, andthe first hole transporting layer comprises the compound.
 28. Theorganic electroluminescence device according to claim 25, wherein the atleast one organic thin film layer comprises a first hole transportinglayer and a second hole transporting layer sequentially from the anode,and the second hole transporting layer comprises the compound.
 29. Anelectronic equipment, comprising the organic electroluminescence deviceaccording to claim 25.